Because you like Daniel LaRusso in The Karate Kid
Clank is the quintessential rational, intelligent robot sidekick. See them in Ratchet & Clank.
A laid-back stoner, Ben Stone wasn't planning on life's ultimate responsibility. See them in Knocked Up.
A wildly brilliant detective, Sherlock Holmes can figure out everything except how to interact with other human beings. See them in Sherlock.
Albus Dumbledore oversees the most unsafe school in recorded history, with Dementors and giant arachnids run amok. See them in Harry Potter Series.
Dory is more than a little forgetful, but she'll always remember to have your back. See them in Finding Nemo.
Sheldon Cooper is brilliant in every way except, well, interacting with any human being. See them in The Big Bang Theory.
When a half-breed breaks the rules, John Constantine deports them straight back to hell. He's trying to buy his way into heaven. See them in Constantine.
Clementine is a beacon of innocence in a dangerous, deadly world. See them in The Walking Dead (Video Game).
Armed guards, FBI agents, notorious serial killers – Hannibal Lecter has bested them all, with time to finish dessert afterwards. See them in The Silence of the Lambs.
Everyone is just a chess piece, and Izaya Orihara is a master player. See them in Durarara!!.
A crabby troll, Karkat Vantas is perpetually angry about his lot in life. See them in Homestuck.