~The girl you just called fat. . . . She's starving herself.~
~The girl you just called ugly. . . . She spend hours putting on makeup and pretenting, just wishing that people liked her.~
~The boy you just tripped. . . .  He is abused at home.~
~That man you just made fun of for his scars. . . .  
He fought for his country.~
~That guy you beat up for being homosexual. . . . 
He committed suicide a few minutes ago.~
~That thirteen year-old girl with a baby that you called a slut. . . . 
She was raped.~
~That man you made fun of for crying. . . . 
His twelve year-old daughter just committed suicide.~

You don't know what's happening in someone else's life.

That bully you just beat up, yes, he was a bully, but he is also abused at home and used by his friends.

The kid that came in late to class that got in trouble, he was on the midnight shift and early morning shift, because if he didn't his mother would lose funding for treatment, his little baby brother wouldn't be able to go to school, his little sister won't get anything for her 8th birthday and his whole family will be on the streets. Kids get awards for good attendence but not for keeping their family alive.