That's very kind of her, but I couldn't possibly impose. And I'm all right, really. I used to live in a place quite similar to this when I was a teenager, actually.
Oh.. umm.. about that. The Joker has a different story every time he mentions his scars. People don't actually know how they came to be-- he might not actually remember. Though I suppose it's possible he does wear the makeup because of them. That makes more sense than most things about him do.