I am fascinated by this, when I was younger I was obsessed with cutting out sleep, experimenting with polyphasic sleep, energy drinks etc.

I'll add one other anecdote that I don't know what it means, but I had a project I was working on that was tight deadline, as a result I was only able to get two hours a sleep a night for about a week. For some reason once I got past the third day my tiredness and desire to sleep seemed to dip considerably, and I found that staying awake when engaged in any activity or discussion was easier. If I was just sitting in a meeting or presentation that I wasn't very interested in I would doze off, but as long as I was engaged I felt like I didn't need to sleep at all.

I really wish we knew more about sleep.