Because you like Elwood Blues in The Blues Brothers
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.
A wildly brilliant detective, Sherlock Holmes can figure out everything except how to interact with other human beings. See them in Sherlock.
It's hard to tell if Dean Winchester cares more about saving the world or his 1967 Chevy Impala. See them in Supernatural.
A bookish know-it-all with a bossy streak, Hermione Granger always stands up for what she believes in. See them in Harry Potter Series.