Because I think sometimes you need somebody to stop you.
DAY 17. FAVORITE DONNA MOMENT
I know a lot of people are annoyed by Donna and her attitude, but I personally love it. She’s not one to take crap from anyone, and especially not any martian. But through that, she’s a deeply caring person, which I find shines through in The Fires of Pompeii, and is reminiscent of The Runaway Bride. In these two cases, the Doctor is practically blinded by rage, whether it is at himself, or the situation, and like Donna says, he needs someone to fall back on. She’s his best friend, and although there are plenty of marriage jokes between them, they do love each other (even if it’s not in that way). She doesn’t think too highly of herself, but ends up being so very important, even if she doesn’t know it.