What could possibly be my problem. I find myself completely blank and thought free at times. Usually when I'm in line at the store or waiting for something that is taking forever, I suddenly go blank, and it feels like my mind is on "Screen Saver" temporarily. What is causing this, I do this when I eat too. I don't feel very aware when I'm eating a meal, or a snack even. When I swim laps or do the stairmaster at the gym my mind goes blank as well.