You know that walkin’-on-air feeling when you’ve aced a test or delivered a slam-dunk presentation? You want to high-five every Tom, Dick and Harry who crosses your path and then some.But what happens when you got a C instead of an A, or missed the mark in your presentation? Do you say to yourself, “Hey, I still did a great job!” Or do you think, “Man, I really blew it.”According to a new study published in the the APA journal Emotion, people who attempt to bolster self-esteem by telling themselves they did a good job—even when they didn’t—actually end up experiencing symptoms of depression and dejection.“My studies showed that those who assessed their performance more positively than what it really was experienced higher depression, performed worse in school (e.g., lower GPA), engaged more in self-handicapping behavior and had lower achievement motivation, compared to those who assessed their performance accurately,” said lead author Young-Hoon Kim, Ph.D., of the University of Pennsylvania.QUIZ: How’s Your Self-Esteem?When people, particularly students, have unrealistic self-perceptions not only will do they lack the motivation for achievement, but the crushing reality of what it actually takes to succeed in life could also result in depression, according to Kim.“Unrealistic positive perceptions are not easy to maintain because our reality—getting jobs, making new friends, trying challenging tasks—does not support them, causing them to get depressed [due to] the conflict between their self-perceptions and experienced reality,” said Kim.Kim faults society for teaching children to grow up with a “we’re all winners” attitude, the one that ensures everyone goes home with a trophy at the end of the game. The fact of the matter is that we’re not all winners all of the time, and we don’t always perform at our highest potential.Sure, it’s great to have a positive self-esteem, but problems arise when we delude ourselves into thinking we really nailed that presentation—even though it’s clear that the client would rather be anywhere else than still listening to us drone on. In this case, a dearth of self-awareness could not only prevent you from recognizing and learning from your mistakes, but it could also affect job security, especially when the thumbs up you give your boss is met with a look of bewilderment and a shake of the head.QUIZ: How Satisfied Are You With Your Life?All in all, yes, it hurts to acknowledge when you don’t perform at your best, and sometimes it feels better to be blissfully ignorant of your misses, but in the long run, it’s better for your career, self-esteem and overall mental health to recognize your strengths and weaknesses.Sure, it might mean a few less high fives over the course of a lifetime, but in the end at least you’ll know the ones you do get will be deserved.