It depends on how you define work and also who is deciding what you work on. I am working on my own startup as a solo founder. Any time, I am not with my family

It depends on how you define work and also who is deciding what you work on. I am working on my own startup as a solo founder. Any time, I am not with my family, working out or eating/sleeping, I am 'working' - about 10-12 hours per day. But not all of that time is difficult (deep) work. I code, I design, I talk to users, I read, I do research, I take notes, I think, I plan. Other than coding, none of those feel like 'work'. Coding feels like work because it is both math difficult and bodybuilding difficult - (not my words, I read them somewhere). I enjoy the autonomy and seeing the impact of my decisions firsthand. I doubt I would have the same hours or energy if I was working where someone else was deciding what I would work on or if I was far removed from the results of the work.