You take this cold, remarkable, difficult, dangerous, borderline psychopath man, and you wonder what might have happened to him had he not met his best friend, a friend that no one would have put him with, this solid, dependable, brave, big-hearted war hero. I think people fall in love, not with Sherlock Holmes or Dr. Watson, but with their friendship. I think it is the most famous friendship in fiction, without a doubt.
Steven MoffatCome on, Rory! It isn't rocket science, it's just quantum physics! -The Doctor (Matt Smith)
Steven MoffatMadge: I don't know why I keep shouting at them. The Doctor: Because every time you see them happy you remember how sad they're going to be. And it breaks your heart. Because what's the point in them being happy now if they're going to be sad later. The answer is, of course, because they are going to be sad later. ~ The Doctor, the Widow, and the Wardrobe
Steven MoffatIf you don't expect to like someone and then you do, that's an incredibly exciting moment.
Steven Moffat