I've only ever felt burnout when I didn't enjoy the job.

I once worked at a job I didn't really enjoy, and I worked 8 hours during the day and often 4 hours coding on my side projects. What's the difference between that and coding 12 hours doing something you love?

I have some experience in it: I was working day-and-night on my own projects at the beginning of my career - gave me a lot of money and experience, but now I know for sure that I could do it with just 20% of efforts - all my best things were written/built after some long rest periods (more than week of rest). All that experience I could learn just in a few weeks but I was too stupid to spend some of my time to read what other people do - I was reinventing all the wheels.

After that I was working in a company, 14-16 hours per day, 6 days per week. After 2 years of such work, at the end of the day I had to spend 5-15 seconds to remember names of my wife and son, my address.

So I decided to never work more than 8 hours per day, preferably less. And you know what? My earnings increased, my relationships with employers are much better now, my health is MUCH better. So I can say for sure - overworking is a waste of lifetime and gives nothing.

Good for you. Hamming worked long hours, neglected his wife and now there's a function named after him in every scientific library running billions of times a day.

Nobody should be forced to work long hours but if they want to, and it works for them - go for it I say.

How do you know he neglected his wife? I found that they did not had children, but could not find anything else about his personal life.

Hamming quote in post 5 ancestors back:

I spent a good deal more of my time for some years trying to work a bit harder and I found, in fact, I could get more work done. I don't like to say it in front of my wife, but I did sort of neglect her sometimes

And he might've achieved that regardless. Study after study finds people have about 6 productive hours a day in them.