I operated on 5 1/2 hours of sleep when I was working the Navy job and the two jobs before that. In fact, even into my college days I was a short session sleeper. Since I have retired, however, my average has crept up to over six 1/2 hours. When I haven't had enough sleep even by my standards, I'm initially sluggish and that permeates my physical as well as mental activity. My waking profile is that as the day gets later, I get more and more alert. It was for that reason that I programmed my main Navy system to send me e-mails about any events that were detected during the previous evening. I didn't have to go looking because my machine told me what went on. I didn't have to guess or search for anything.