We would probably be a lot happier if we could manage to think about what we're doing, at the time we're doing it.
Recently, I was very nearly run down by a woman driving a minivan in a grocery store parking lot.
As I watched my apparent doom racing toward me, I clearly saw that she (the driver) was looking away from the windshield, apparently fascinated by something inside the cabin of her vehicle.
Fortunately, I narrowly (miraculously) escaped an intense encounter with her front bumper. I shouted, she looked shocked, and we both went our way.
“What was she thinking?” I wondered.
The simple answer is: she was thinking about something other than what she was doing.
It seems to me we spend a lot of time thinking about things other than what we're doing: checking e-mail while we're talking on the phone, talking on the phone while we're driving our car, reading while eating, and so forth.
Perhaps we would be happier (not to mention safer) if we could simply manage to do what we are doing when we are doing it.