I do. Very often. i always feel very weird and people in mmorpgs i use to play called me the most random person they knew.
My. Mind. Never. Ever. Stops. It drives me bonkers and... makes me feel bonkers. Funny enough, though, at this moment I only have mundane and sane thoughts.
Random thoughts are terrific if you need to entertain a child, too. I use to easily just make up silly stuff for my niece.