Because you like Larry Flynt in The People vs. Larry Flynt
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.
A dreamy space cadet, Luna Lovegood has never met a conspiracy theory she didn't believe in. See them in Harry Potter Series.
Severus Snape is a misanthropic potions teacher with a vindictive streak. See them in Harry Potter Series.
After surviving consecutive fights-to-the-death (damn you, President Snow!), Katniss Everdeen is thrust to the front lines of a real war. See them in The Hunger Games .
Chandler Bings keeps his friends on their toes with his cutting wit, all the while trying to discover his own place in life. Could he BE any funnier? See them in Friends.