When I was 20, I always wanted to finish a job without sleeping, because I'd come back with more neat ideas, and lose even more money/time. I often slept only 3 or 4 times a week, but had no trouble going 15 hours to catch up. Around 20 years ago, I had no scheduled responsibilities, and the beginning of computer addiction, leading to random sleep periods. I also had to stoke a wood fire, so it was better to be up every four hours in winter. This was fine, except when I had to sleep "regular" hours to avoid noise and other disturbance. If I get over-tired, things get bad. This year, I have been working hard at making the inter-sleep periods briefer, but here I am now, in one. To re-establish a circadian rhythm, I started with regular meal times, since I can control that easier than falling asleep. There's still a long way to go, but I did manage to attend a meeting while fully awake for the first time in decades.