Because you like Marmee March in Little Women
Emily Fields has been very guarded, careful of whom she trusts and reveals her secrets to. See them in Pretty Little Liars.
The only defense Earth has against alien invaders are giant robots in the hands of pilots like Kaworu. See them in Neon Genesis Evangelion.
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.
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.
Trying to get through school without being a burden to anyone, Tohru Honda stays cheerful despite her difficulties. See them in Fruits Basket.
Titus Andromedon will show you the ropes, help you with your problems, and sing at you constantly, whether you like it or not. See them in Unbreakable Kimmy Schmidt.
A benevolent madman with a blue box, The Doctor is traveling through time and space to heal the wounds of the universe. See them in Doctor Who.
An escaped convict on a mission, Sirius Black is brooding, brave, and reckless. See them in Harry Potter Series.
Albus Dumbledore oversees the most unsafe school in recorded history, with Dementors and giant arachnids run amok. See them in Harry Potter Series.
John Watson is haunted by his past (who isn't) but he's starting to branch out with some help from a world class detective. See them in Sherlock.