Patricia was a 15-year-old high school cheerleader in her 10th year of Catholic school.

Chuck was a basketball star, a senior from the rough side of town.

One night after a high school mixer where everyone danced to jukebox music, Chuck and a friend offered Patricia a ride home. Chuck held Patricia's hand in the back seat, and when they got to her house, he walked her to the door. "Then he put both arms around me and kissed me gently on the lips," recalls Patricia. "I thought for a fleeting moment that I was floating with angels in heaven."

The next instant, their bubble was burst when Patricia's father turned on the porch light.

"It was 49 years ago and I still remember nearly all the details," says Patricia. "I was suddenly desirable," she explains. "I was kissworthy—and oh my goodness, that was enough self-esteem to propel me into a lifetime of feeling good about myself."

Love & Sex

Beginning in our late teenage years and early 20s, we develop and internalize a broad, autobiographical narrative about our lives, spelling out who we were, are, and might be in the future, says Dan McAdams, a psychologist at Northwestern and author of The Redemptive Self: Stories Americans Live By. The story is peppered with key scenes—high points, low points, and turning points—and a first experience can be any of these. "These experiences give us natural ways to divide up the stories of our lives—episodic markers that help us make sense of how our life has developed over time," McAdams explains.

Part of why firsts affect us so powerfully is that they're seared into our psyches with a vividness and clarity that doesn't fade as other memories do. You may not remember the 4th real kiss you ever had, or the 20th—but you almost certainly remember your first. This is known as the primacy effect.

When people are asked to recall memories from college, 25 percent of what they come up with draws from the first two or three months of their freshman year, says David Pillemer, a psychologist at the University of New Hampshire. What people remember most vividly are events like saying goodbye to their parents, meeting their roommates for the first time, and their first college class. In fact, when psychologists ask older people to recall the events of their lives, the ones they most often name are those that occurred in their late teens and early 20s. We're also better at recalling the world events, music, books, and movies—as well as the cultural events such as the Academy Awards or the World Series—that happened during the early parts of our lives. This "early-life memory bump" occurs because that's when we have the most first experiences, explains Jefferson Singer, a psychologist at Connecticut College who studies autobiographical memory.

Consider a first kiss or sexual encounter. These can generate sensations so new and unfamiliar that the experience feels almost unreal. "Someone can be a primitive neophyte when it comes to writing, but when you get them to talk about their first kiss, you see eloquence, poetry, metaphor, synecdoche, and hyperbole," says John Bohannon III, a psychologist at Butler University who studies first kisses. That sensation of disembodiment—pleasurable during a kiss, aversive when you first suffer the death of a loved one—is common in first experiences, as are feelings of heightened reality or unreality.

Intense emotional sensations etch first experiences deeply into memory, creating what psychologists call "flashbulb memories." Memories like our first kiss or tryst, our first glimpse of the ocean, our first day of school, or the birth of a first child engage all our senses simultaneously.

Besides emotional engagement, these experiences also pack a heavy dose of novelty. "Novelty drives up dopamine and norepinephrine, brain systems associated with focus and paying attention and rewards," explains anthropologist Helen Fisher, author of Why Him? Why Her?

A first romantic relationship has one critical novel element: "It's the only time you're ever in love where you've never had your heart broken," says Laura Carpenter, a sociologist at Vanderbilt University and author of Virginity Lost: An Intimate Portrait of First Sexual Experiences. "You can have better relationships after that, but there's never again one where you've never been hurt ."

"Powerful first relationships can stamp a template in your mind that gets activated in later interactions,"says Susan Andersen, a psychologist at NYU who studies mental representations of significant others. If you meet someone who reminds you even a little of an ex—whether it's a physical resemblance or a similarity in attitudes, gestures, voice, word choice, or interests—it may engage the representation you have in your memory, says Andersen. The effect is called transference. And since your first love, by virtue of its novelty and emotional significance, is potentially your most salient, it may well be the representation that's summoned when you meet someone new, forging the lens through which you see new relationships.

It's not just a person's qualities that get transferred in your mind—your old feelings, motivations, and expectations are also reactivated. If someone new reminds you of an ex you still love, Andersen's studies show, you'll like that new person more, want to be close to them, and even start repeating the behaviors you engaged in with your ex. "The behaviors I'm engaging in will lead this new person, temporarily at least, to actually confirm my expectations," says Andersen. "By interacting in a particular way, I will draw out of this new person behaviors my ex used to engage in. That's expectation becoming reality."

Loss

In Vladimir Nabokov's Lolita, the tormented antihero Humbert Humbert describes Annabel, a childhood neighbor who loves him passionately for one summer, then dies of typhus. "I leaf again and again through these miserable memories," writes Humbert, "and keep asking myself, was it then, in the glitter of that remote summer, that the rift in my life began?"

First loss differs qualitatively from later losses because it submerges us in the icy reality that we're in constant danger of losing the people we love most—a concept we grasp intellectually at a certain age, but which doesn't feel real until it actually happens to us.

"We're wired for attachment in a world of impermanence," says Robert Neimeyer, a psychologist at the University of Memphis who studies how people draw meaning from loss and grief. "How we negotiate that tension shapes who we become."

Early loss can poison your ability to trust or feel safe, or give yourself fully in subsequent relationships, explains Singer. There's a strong link between early loss and depression, and early loss is also associated with diminished ability to form later attachments.

But many people find that after surviving a painful loss, they emerge more resilient. Optimistic people take loss better than less optimistic people, as do people who grow up with strong, secure attachment to their caregivers.

But the biggest predictor of resilience in the face of loss is "sense-making," weaving the experience into a larger narrative about who we are and what our lives are about, says Mary-Frances O'Connor, a behavioral scientist at UCLA who studies grief. Robert Neimeyer's father committed suicide when Robert was a child, for instance, and he dedicated his life to studying how people draw meaning from grief.

People struck by loss or trauma at an early age—such as victims of crime or abuse—are at risk of drawing unwarranted conclusions about the world and their own place in it. Maybe your first boyfriend abused you. You may mistakenly infer that you're not careful enough—when the truth is that it could have happened to anybody.

That's the catch with first experiences. Because they're memorable, they come readily to mind and we overgeneralize when drawing conclusions about what kind of person we are. Positive first experiences can inspire us for a lifetime, but negative ones can be hard to get past.

So if you're overly focused on a negative event as a turning point in your life, ask yourself: Is what happened truly a reflection of who you are? Or would others have made the same choices given the same circumstances? "In repeated experiences, we understand the situational factors outside ourselves," says Singer. "But the first time, we don't have the context, so we're more likely to see it as a reflection on our own character."

Lies

Two women recounted the story of their first lie to Bella DePaulo, a psychologist at the University of California at Santa Barbara who studies deception. The first one told a story about how she wanted to go out one night as a child but was barred from doing so by her father. So she went anyway and lied to him about where she'd been. When he cluelessly swallowed the whole story, she realized she had a new talent. She lied freely from that moment on.

The other woman told a story about how, as a girl, she was very curious about her sister's boyfriend. One night she snuck into a room with a phone extension and listened in on their conversation. When her father walked in and caught her in flagrante delicto, she panicked, blurting, "I was just cleaning the phone!" Guilt-stricken over the lie, she immediately confessed and apologized, resolving never to lie again.

A first lie crosses a line. You recognize a capacity you didn't realize you had. For the extremely honest or the extremely dishonest, the lie may reveal character: a decision never to repeat the act, or the realization that this is a new way to behave. But for many people between these two poles, the consequences of a first lie depend on one's reaction to it, says DePaulo. If we do something we shouldn't—say, shoplifting—and get caught and punished, we're likely to internalize the lesson that stealing is wrong, incorporating it into our value system. But if no one finds out, we may decide it's no big deal.

"First experiences tell you something about yourself and what you're like in a new situation," explains DePaulo. "It's testing the social environment and seeing how other people react, but it's also testing who you are, how you think of yourself, and whether you want to be that person."

If you get a thrill out of lying, it's easier to cross that line the next time.

"It's called the abstinence violation effect," explains Singer. "If I'm willing to make that first slip, then what's the point in holding on? Now that I'm now no longer a dieter, I might as well have another cookie." The principle applies not only to straying from a diet but also to major transgressions. If you're a soldier, your first kill may force you to reflect on death and morality. But killing someone may not feel like such a big deal the second time around.

With transgressions, as with other first experiences, it's important to remember that one action doesn't define you. "When counselors treat addicts who have fallen off the wagon, they tell them, 'Look, you haven't relapsed, you've had a slip,'" explains Singer. "If you use the fallacy of saying, 'Oh, well, it's over now,' then you can easily rationalize taking the next drink and the next and the next and it will be a relapse. But a slip can be corrected."

Success

In 1982, before Michael Jordan was Michael Jordan, he was a student at the University of North Carolina. He played good basketball, but as a 19-year-old freshman, he was constantly overshadowed by upperclassmen. When North Carolina entered the NCAA championship game against Georgetown, though, something changed in Jordan's play. In the first three quarters of the game, he scored 14 points and grabbed nine rebounds.

It wasn't enough. Georgetown, led by freshman superstar and future NBA powerhouse Patrick Ewing, was winning 62 to 61, with only 17 seconds left in the game. Then, when it looked like the game was over, Jordan made one of the most famous shots in basketball history: a 16-foot jump shot that won the game and earned North Carolina the championship.

That first game-winning shot was a turning point, Jordan recalled in later years. It gave him the confidence that he could come through in a clutch. For the rest of his career, especially when he needed to muster the intense concentration and Zen calm necessary to shoot free throws, he would summon up that moment to bring him into a winning state of mind. "He used that shot, performing in that pressure situation, as the foundation for his confidence in taking other big shots," says Richard Ginsburg, an athletic coach and author of Whose Game Is It, Anyway? "He'd tell himself, 'I've done this before, I can do it again.'"

Game-winning shots and home runs—as well as the times you ace an exam, nail a job interview, or win a standing ovation—provide potent fodder for your sense of identity as a successful person. "You think, 'I succeeded in this clutch situation, now I know I'm a clutch player,'" explains Singer. "It's revealing something in your character that wasn't clear before, telling you, 'This is something I can do. This is who I am.'"

"I remember the time I first won a tennis match against my father," says Tim Gallwey, author of the classic book The Inner Game of Tennis. Gallwey's father had promised him a new racket if he won. Gallwey was 13 at the time, and had been playing in state tournaments. During the match, he was torn between wanting to win a new racket and not wanting to beat his father. When he won, he felt regret and compassion for his dad, who'd just been defeated by his own son, but was also elated by victory, glowing with a sense that his abilities had reached a new height. "That sense of self-worth is very precious," says Gallwey.

Of course, first failures can be as memorable as first successes. If you flunk a test or miss an easy pop fly, you may start to feel like a loser. And failure is always a possibility. But what separates world-class performers from the rest of us is the ability to put negative experiences behind them (see "Getting Past the Past" below).

"Once you can see yourself doing something—once you can experience it and feel what it's like—it changes you,"explains Ginsburg. "The best performers are good at forgiving themselves, dropping failure from their mental bandwidth quickly so that they can focus on the positive." If you can do that, you may strike out many times, but you'll always be the person who hit that grand slam—which in turn will breed further success.

First successes often take the form of "redemption sequences," wherein a bad event suddenly turns good, says McAdams—like when you defy the odds in a basketball game you're losing by sinking a winning buzzer-beater with seconds left on the clock. "The construction of redemption sequences in life is a very common narrative strategy," he adds, "and one that seems to bring with it a certain sense of resilience."

A single win may not be sufficient to boost your confidence permanently. True confidence comes from the gradual accumulation of self-efficacy over a long period of successes. But a dramatic first triumph can inspire and motivate you and transform your self-conception from "I'm a loser" to "I'm the kind of person who hits grand slams."

And a first success can also uncover abilities you didn't realize you had. Days before he died, I interviewed George Carlin. Toward the end of our conversation, I asked him about the first time he made his mother laugh.

"I noticed the moment something had happened," Carlin immediately recalled. "This was when Iwas very young. My mother laughed fairly frequently. But I knew the difference between her social laugh and her really spontaneous laugh when she was caught off guard and amused—I saw that in her and it registered with me. It meant Ihad said something witty. It was a little mark along the way, a little badge of honor." —Jay Dixit

Setup For a Self-Fulfilling Prophecy

Expectations about how an experience "should" feel can prime you for a lifetime of disappointment.

A negative first relationship can doom people to get trapped over and over again in self-destructive relationships. The reverse effect applies also. If your first relationship is healthy and positive, you may expect new people to be similarly friendly and safe—causing you to feel fondly, disclose your emotions, and build intimacy with that new person.

Losing one's virginity is an experience often subject to self-fulfilling expectations. People who consider their first sexual encounter to be a momentous turning point and find that it is indeed positive tend to wait for another loving relationship before they have sex again, says Laura Carpenter, a sociologist at Vanderbilt University and author of Virginity Lost: An Intimate Portrait of First Sexual Experiences. But if they're rejected by their partner, such people feel worthless—as if they've lost a special part of themselves. "A number of them felt they didn't have the right to say no to future sexual partners because they were already 'soiled' and 'ruined,'" says Carpenter. "They get involved in relationships they don't want and feel they have to have sex because they've already had sex. It's a spiral."

As with other first experiences, the loss of virginity can be a rite of passage—an irreversible transition from a state of ignorance to a state of knowledge. "Like a teen-ager learning to drive or a surgeon mastering her craft, you're knifing off the old self and building this new self," says Carpenter. "Whether it's what sex is about, a body of knowledge about religious mysteries, or medical skills, you've gained this special knowledge and you can never go back."

Getting Past The Past

You can't change the past, but you can look at it differently. Here's how.

Make a choice. Decide to stop dwelling, suggests Susan Nolen-Hoeksema. List the pros and cons of dwelling—an exercise that will feel absurd, since cons will vastly exceed the pros. Say to yourself, "I know it's hard, but I choose to move forward."

Contain your rumination. Schedule limited blocks of time to wallow—say, 15 minutes twice a day. You're compartmentalizing your grief—and you'll soon get bored of it and move on.

Do a reality check. Maybe you find yourself thinking, "I'll never be happy again." Stop. True, nothing will ever be exactly the same. But there's no reason you can't find happiness in the present and future, with new people and new experiences.

Do not confuse the path with the destination. Maybe you lost a youthful love and can't let go. Maybe you got fired and you feel like a failure. Clarify your values—creativity? Love? Recognize that you don't need that particular job to do creative work. You don't need that particular partner to have a loving relationship. Continue on your path.

Get present. Join a gym, take up a hobby, find a cause, and schedule time with friends. "The best way to break free of living in the past is to get focused on the present and the future," says psychologist Jefferson Singer. "Take risks and do concrete things to create new experiences for yourself in the here and now."