I have this problem too.
I try to use my senses at those times, and breathe deeply and stop fidgeting (not easy for me to do). I imagine I'm watching a movie and concentrate on what is happening right now, in front of my eyes.
My imagination is more entertaining and stimulating than TV . To numb my mind, I actually watch TV . I wish I could write it all down. I'd be churning novels out if I could capture this stuff (or had the motivation to).
"Charlotte sometimes dreams a wall around herself. But it's always with love - So much love it looks like everything else. Charlotte Sometimes - So far away, glass sealed and pretty." - The Cure