I like to think that when these fellas knocked the door, they were asked 'who's there' and they replied 'doctor'. Thus beginning the greatest knock knock joke ever. Dr Who's fine and all, I like the wee police box and the magic pen with the LED on it, But the fans kinda can be crazy though. Its maybe not some much that the fans love it so much, I think its that a) they are usually younger than most geeks/fanboys and b) they have the full might of the BBC to force it night and day on everyone else. They even have a Dr Who proms night, featuring music from the show! On the upside Dr Who is one of the easier characters to dress up as for halloween and they have found the best way to make the recasting of the main character not only make sense but be integral to the show itself. James Bond has never explained any of that and don't say it's a disguise. I've seen what Connery this constitutes as a discuise for 'blending in' to japanese culture.
PS. Suffice to say, my favourite doctor was Rowan Atkinson.