Because you like Sutter Keely in The Spectacular Now

Puss In Boots is a suave, honorable ladies man/cat who's not above playing cute to get you to let down your guard. See them in Shrek 2.

John Watson is haunted by his past (who isn't) but he's starting to branch out with some help from a world class detective. See them in Sherlock.

Finn is the world's last human who's "all about" understanding right and wrong. See them in Adventure Time.

A benevolent madman with a blue box, The Doctor is traveling through time and space to heal the wounds of the universe. See them in Doctor Who.

Brilliant, violent, and only a little insane, the Joker doesn't listen to anyone except the voices in his head. See them in DC Extended Universe.

L is enigmatic, child-like, and one of the smartest people in the world. See them in Death Note.