Because you like Oskar in Let the Right One In

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.

What Ron Weasley lacks in motivation and book smarts, he makes up for in loyalty and street smarts. See them in Harry Potter Series.

With great power comes great responsibility, but Peter Parker always seems to get the short end of that bargain. See them in Marvel Cinematic Universe.

Smart and sensitive Sam Winchester tried to escape the family business, but ghosts have a way of haunting you. See them in Supernatural.

It's hard to tell if Dean Winchester cares more about saving the world or his 1967 Chevy Impala. See them in Supernatural.

Castiel might be an immortal angel, but the human world is still more than a little confusing. See them in Supernatural.

A wildly brilliant detective, Sherlock Holmes can figure out everything except how to interact with other human beings. See them in Sherlock.