Because you like Emmett Richmond in Legally Blonde
Smart, sarcastic, and loyal, Stiles Stilinski doesn't just want to be the sidekick in someone else's life. See them in Teen Wolf.
Aang is already a master airbender and once he learns to manipulate water, earth, and fire, he'll be truly unbeatable. See them in Avatar: The Last Airbender.
Sheldon Cooper is brilliant in every way except, well, interacting with any human being. See them in The Big Bang Theory.
SpongeBob SquarePants lives in a pineapple under the sea. Absorbent and yellow and porous is he. See them in SpongeBob SquarePants.
L is enigmatic, child-like, and one of the smartest people in the world. See them in Death Note.