Because you like Rita Vrataski in Edge of Tomorrow
Albus Dumbledore oversees the most unsafe school in recorded history, with Dementors and giant arachnids run amok. See them in Harry Potter Series.
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.
Eren Jaeger will erase the Titans from this world until not a single one remains. See them in Attack on Titan.
Bella Swan thinks of it as her job to help her parents and protect her friends, even though it often ends up the other way around. See them in Twilight.
Tracy Turnblad's got rhythm, and she's determined to share her dance moves with the world. See them in Hairspray.
Alison DiLaurentis believes you're always better off with a really good lie. See them in Pretty Little Liars.
Jenko was top dog in high school. Now he's bottom of the pack in the police academy. See them in 21 Jump Street.
Anyone who's said "Don't worry, it's just a dream" never met Freddy Krueger. See them in A Nightmare on Elm Street.
Willow Rosenberg may be a witch who can defeat the forces of evil, but she still gets emotional over kittens on the Internet. See them in Buffy the Vampire Slayer.