I'd like to think that everyone does from time to time.
However, I find that sometimes I get into thinking that I should sit down and force myself to doodle. And I can guarantee that anything I scribble during one of these sessions will be rubbish. The secret to good doodling (I reckon) is to make sure you're doing something else at the time.
Some of my 'best' doodles have dribbled out of my pen while I'm waiting for some artwork to upload, or if there's something undemanding on the TV. I guess there's some clever biological thing going on which allows your subconscious (or something) to relax - by not concentrating on what's happening on the page, your brain is free to do all sorts of things.
I still end-up with a load of nonsense, but once in a while something will trigger a thought, which in turn might evolve into an idea and sometimes a finished piece of art.
So if you're not doodling, you should be - just make sure you're doing something else at the same time.