Unlike many of you, I don't watch Dr. Who (after starting my post that way, I considered continuing in rhyme but I'm lazy) and I only know the very general plot. But seeing all the posts about it here and across the general interwebs this weekend about the naming of the new doctor, I'm left with a question!

SO

I understand there is a new doctor every few years...is this because it's a part of the position of Dr. that one can only be a time traveller (that is what he does, right?) for X # of years? Like being President of the US.

OR

Is it just that the actors move on when they move on, and the show ignores this and just inserts a new doctor but pretends nothing has changed. Like Aunt Viv in Fresh Prince or Becky in Roseanne.