I remember reading this published insight from Marissa Mayer a few months ago:
Burnout is caused by resentment
Which sounded amazing, until this guy who dated a neuroscientist commented:
No. Burnout is caused when you repeatedly make large amounts of sacrifice and or effort into high-risk problems that fail. It’s the result of a negative prediction error in the nucleus accumbens. You effectively condition your brain to associate work with failure.
Subconsciously, then eventually, consciously, you wonder if it’s worth it. The best way to prevent burnout is to follow up a serious failure with doing small things that you know are going to work. As a biologist, I frequently put in 50-70 and sometimes 100 hour workweeks. The very nature of experimental science (lots of unkowns) means that failure happens. The nature of the culture means that grad students are “groomed” by sticking them on low-probability of success, high reward fishing expeditions (gotta get those nature, science papers) I used to burn out for months after accumulating many many hours of work on high-risk projects. I saw other grad students get it really bad, and burn out for years.