Because you like Egon Spengler in Ghostbusters

Milo Thatch is an enthusiastic researcher without cynicism. See them in Atlantis: The Lost Empire.

Victor Frankenstein can create life, so he's pretty awesome if he says so himself. See them in Frankenstein.

It's a race against time to develop his theory of the origins of the Universe before Stephen Hawking's body and mind give out. See them in The Theory of Everything.

Both a noble district attorney and a psychopathic villain, Harvey Dent proves some men really can have it all. See them in DC Extended Universe.

One of the best in the magical world, Mad-Eye has the battle scars to prove his dedication to such a dangerous job. See them in Harry Potter Series.

A karate master/rocket scientist/squirrel, Sandy Cheeks is the only one who can clean up the other resident's messes in Bikini Bottom. See them in SpongeBob SquarePants.

Dewey Finn will rock you. He feels rock and roll in his blood and guts. See them in School of Rock.

C is for cookie, and that's more than good enough for him. See them in Sesame Street.

In the simplest terms, in the most convenient definitions, people consider Brian a nerd. But he's more than that. See them in The Breakfast Club.

Nicholas Angel is super-dedicated to his job as a police officer. Maybe a little too dedicated. See them in Hot Fuzz.

Kesuke Miyagi is a karate expert who thinks the best way a scrawny high schooler can learn how to defend himself is by washing every surface in sight. See them in The Karate Kid.

Nick Carraway is the perfect observer: always there for the events, but never too involved. See them in The Great Gatsby.