Because you like Emmett Brown in Back to the Future

Peter Venkman's "research" projects are designed to get undergraduate students to sleep with him. Though it turns out he can bust ghosts. See them in Ghostbusters.

A scary monster on the outside, James P. Sullivan is really a softie on the inside. See them in Monsters, Inc..

Will Turner is an earnest, lovelorn blacksmith's assistant with an adventurous spirit. See them in Pirates of the Caribbean: the Curse of the Black Pearl.

A no-nonsense pro, Agent K has dedicated his whole life to his job. See them in Men in Black.

The destroyer, Drax lives for one thing and one thing only: revenge. See them in Marvel Cinematic Universe.

Ted is a cursing, smoking, drinking teddy bear who's anything but cuddly. See them in Ted.

Danny Zuko's car is auto-matic. Its system-matic. Its hyyyyydro-matic. Why, its greased lightning! See them in Grease.

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.

Morpheus is wise enough to see into the bones of the world. See them in The Matrix.

For Wreck It Ralph, it's not easy being the bad guy. Especially when you've been designed to destroy but really desire love. See them in Wreck-It Ralph.

Others see him as the town nutcase, but Flint Lockwood knows his inventions will change the world someday. See them in Cloudy with a Chance of Meatballs.

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.