Because you like Joel Barish in Eternal Sunshine of the Spotless Mind

Optimus Prime is a shapeshifting sentient robot leading a team of robots to stop evil from taking over. See them in Transformers.

Lelouch vi Britannia is a high school student by day, masked destroyer of tyrannical empires by night. See them in Code Geass.

Keren Walker is a socialite looking to avoid work, keep a constant buzz, and be as snarky as possible. See them in Will & Grace.

Yuri is living in the afterlife, which takes the form of a high school where no one dies. But if you follow the school's rules and live a "normal" life you vanish. See them in Angel Beats!.

Aragorn is the one true king, a title he is too humble to accept. See them in The Lord of the Rings.

People think that because Tris is small, or a girl, or a Stiff, she can't possibly be cruel. But they're wrong. See them in Divergent.

Everyone Barney Stinson knows is getting married or pregnant. But he's just getting more awesome. See them in How I Met Your Mother.

Few high school students could be less concerned with labels. See them in Ouran High School Host Club.

Angel is fighting as best as he can, but the disease might be too powerful for even his strong, positive energy. See them in Rent.