I often wonder if da Vinci ever had time to sleep. Such an amazing man.
He catnapped (that tidbit even made it into a Seinfeld episode), basically stayed up all the time, but slipped into 15 minute or so naps every three or four hours. Aristotle Onassis’ tip on how to succeed was to get by on 5 hours of sleep instead of 8, it gives you a couple extra months a year, something like that. People I’ve known who get a lot done seem to fall in the “never sleeps” category. :’)
OTOH, Leonardo’s mood swings may have been caused by his lack of sleep, and vice versa — he tended not to finish projects. His biggest attempted project was a canal to reroute the Arno River, eliminating malarial marshes, creating a navigable channel for seagoing ships, denying a water supply to archrival Pisa, and creating a large (and taxable) irrigation system to support much more robust agriculture. He didn’t take care of the personnel issues, so the job went to some idiot related to some other idiot in the city gov’t, and it got completely effed up.