Yea there seems to be some thing of a positive feedback loop that one can get into. I’ve experienced this multiple times too. When I had a boring and easy job I had all sorts of aspirations of doing a side business or learning some new stuff etc. I ended up doing none of that and mostly playing games instead. When I had a busy (but interesting) job I ended up doing side projects, socializing a lot more and generally being more productive outside of work. Something like momentum from one activity carrying through to others.