Here's something fun from Discover magazine.
Everybody knows what it is like for our minds to wander, and yet, for a long time psychologists shied away from examining the experience. It seemed too elusive and subjective to study scientifically. Only in the past decade have they even measured just how common mind wandering is.
These experiments show that we spend about 13 percent of our time zoning out. But when we are drunk, that figure doubles. In other words, inebriated subjects report less mind wandering only because they are less aware of their own minds.
I zoned out twice--that I'm aware of--putting this together.