I think the point he made was rather the opposite. He works 10-12 hours a day, 60 hours a week, 6 days a week. He needs seven to eight hours of sleep, like a normal person. He specifically mentioned that he never was much into doing all-nighters and that he experimented with working different times of the day. So he'd start in the afternoon and then continue until deep in the night when he was younger whereas having kids and a family caused him to shift to having an early start instead and run a more normal schedule.

That sounds like an intense schedule for sure but not really that insane. He's not super human and just staying in shape, and well rested is what has allowed him to do this for decades on end. Work life balance and taking care of his family is just part of that deal as well.

I notice that the quality of my own work is simply much better when I'm well rested and that beyond a certain point, the most productive thing is for me to simply take some rest or do something non work related. The rare case that I need to work on something late, I pay the price the next few days. It all averages out in the end in terms of productivity.

Grinding away at a problem for hours is simply draining. Often those problems melt away the next morning after I sleep a bit. Your brain doesn't stop working when you do. The hard work is immersing yourself in the problem and absorbing all its facets and then calmly reflecting on all the assumptions you are making. Generally, if you are stuck you need to find out which of your assumptions it is that is wrong. I've woken up with fully formed solutions in my head for seemingly unsolvable issues or bugs that I fought with the previous day so often that I actually rely on this happening a lot these days. So, I generally stop working around 6-7 pm and I'll park harder issues until I'm well rested in the morning or after a weekend.

I don't work on the weekend. The weekend is for resetting my brain. Just as important as sleep is. The most productive use of that time is allowing that brain reset to happen. Getting frustrated and stressed is counter productive. It leads to poor sleeping patterns and stuff just piles up. Take a break, relax.