The moment I knew I needed more sleep was four years ago, when I learned the value of sleep -- the hard way.
I'd just returned home after a week of taking my daughter on a tour of colleges, and the ground rule was no BlackBerry during the day, so I stayed up very late to catch up on work.
Next thing I knew, I was lying on the floor, bloodied. I had passed out from exhaustion and banged my head on the way down.
The result was a broken cheekbone and five stitches under my eyebrow.