They're not the same thing.
Though a rather good case can be made for repeating oneself being the result
of not having anything more to say, in this particular case we're dealing with
two different phenomena. Not having anything more to say is a result of running
out of topics that interest me, that are distinct enough so that having examined
one, there's still something left to say about another. On the other hand, even
if I had an unlimited list of new topics to examine, I'd be more than capable of
repeating myself, both in style and in content.
Go to: My greatest fear.