Because you like Liesl von Trapp in The Sound of Music
Although Penny's friends have genius-level IQs, they regularly come to her for advice and insight. See them in The Big Bang Theory.
Foul mouthed and disturbingly comfortable with violence, Hit-Girl is a precocious assassin who doesn't need anyone's protection. See them in Kick-Ass.
Mystique is a shape-shifting mutant who, after too many disappointments, does not want to co-exist with humans. See them in X-Men Series.
Olivia Benson brings order to a world full of chaos. And she never forgets who she's fighting for. See them in Law & Order: Special Victims Unit.
An aristocrat-turned-tomb-raider, Lara Croft does her best thinking while plunging off cliffs. See them in Lara Croft: Tomb Raider.
Abandoned by her parents, Rey made her living selling scrap metal and got used to being her own friend and teacher. See them in Star Wars Series.
An infamous vampire, Alucard is a one-man killing machine with a philosophical side. See them in Hellsing.
You don't teach a class called "How To Get Away With Murder" without knowing a thing or two about getting away with things. See them in How to Get Away with Murder.
A good guy who's made some bad choices, Scott Lang is driven in his quest for redemption. See them in Marvel Cinematic Universe.
Tobias "Four" Eaton is only afraid of four things, but you should probably be afraid of him. See them in Divergent.
Fox Mulder is a devoted believer in aliens, monsters, and that the truth is out there. See them in The X-Files.