Because you like Zim in Invader Jim
Butters Stotch is a kind-hearted student who likes ladybugs, Charlie's Angels, art class, baby-back ribs, and Little Bunny Foo Foo. See them in South Park.
What Troy Barnes lacks in common sense, he makes up for with heart. See them in Community.
Klaus Baudelaire's photographic memory saves the lives of his siblings many times over. See them in Lemony Snicket's A Series of Unfortunate Events.
Deadpool thinks life is an endless series of train wrecks with only brief commercial-like breaks of happiness. See them in Deadpool.
If Lisbeth Salander can hurt a bastard who deserves it by digging up stuff about him, she feels good. See them in The Girl with the Dragon Tattoo.
Point the fun-loving Pippin Took towards second breakfast, and he's one happy hobbit. See them in The Lord of the Rings.
Give in to the dark side with vampire Lestat; it's more fun. See them in Interview with the Vampire: The Vampire Chronicles.
Villanelle is a hired assassin who loves committing murder as much as she loves dressing up in fancy pink ballgowns. See them in Killing Eve.
Tonya Harding has been shoved around her whole life. She just wants to feel free. See them in I Tonya.
Meat Boy tenaciously throws himself into danger, and when he fails, he immediately gets back up and tries again. See them in Super Meat Boy.