There is hard work and there is insanely hard work.
Relaxing is work because in that moment, there are ideas of how to make things better. When not working, thinking of working is still working, thinking of solving problems and solving problems could be relaxing too.
Jensen Huang of NVIDIA said so.
Do you agree with him? Well, sometimes, some work could be relaxing, when I leave my laptop and want to relax, creating a recipe, which is still work is relaxing for me.
But there are some cooking that is real work for me, the bulk cooking of course. Haha, but it could be fun too.
Yes, I've noticed that difference with not actively working but still passively working somewhere in the background. I used to dislike it a lot, since it's kind of exhausting to think about work when not working. But I've had a change of heart when some of the best ideas came via that process.