Because you like Astrid Farnsworth in Fringe
Bella Swan thinks of it as her job to help her parents and protect her friends, even though it often ends up the other way around. See them in Twilight.
Jenko was top dog in high school. Now he's bottom of the pack in the police academy. See them in 21 Jump Street.
It's easy for Brian O'Conner to fake his way into the world of extreme racing because he's been popping cars since his teenage years. See them in The Fast and the Furious.
Dominic Toretto lives his life "a quarter mile at a time", and he burns through those miles faster than anyone. See them in The Fast and the Furious.
Percy Jackson is an ordinary student thrust into the world of myth come alive. See them in Percy Jackson & The Olympians: The Lightning Thief.
He's an eccentric pirate making it up as he goes along. He's Jack Sparrow, savvy? See them in Pirates of the Caribbean: the Curse of the Black Pearl.
Homer Simpson is a beer-loving disaster in charge of nuclear safety in Springfield. Everybody run! See them in The Simpsons.
Underneath her brassy, sarcastic exterior, Olive Penderghast is more sensitive than she pretends to be. See them in Easy A.
While he might be too cool for school, Soul isn't too cool to do the right thing. See them in Soul Eater.
Although Penny's friends have genius-level IQs, they regularly come to her for advice and insight. See them in The Big Bang Theory.