It's hard to be yourself when all you can think about are the negative things people have told you.
"You're only pretty when you straighten your hair"
"I want to become a plastic surgeon so I can help people like you"
"You need a nose job"
"Everyone in the alto section hates you"
"You need to be brought down a couple of notches" (in regards to confidence levels)
"You're too blunt"
"Don't worry, I stick up for you when other people are gossiping about you"
"You have a mean face"
Sometimes you just need to be reminded that you are good enough. That the "you" who you are is the "you" you should be. (Sounds like something straight out of Dr. Seuss.)
But seriously, say something nice to someone today. You never know what negative things they were told 10 years ago that they still remember today...