Some people might enjoy the work they do so much that it feels better to keep doing that in their spare time rather then having a hobby, time with friends, part

Some people might enjoy the work they do so much that it feels better to keep doing that in their spare time rather then having a hobby, time with friends, partner, errands (specially those), etc. It's not healthy in the long term but I can see why someone would choose that path and it doesn't have to mean this person "doesn't have a life".