> 40h/week paying the bills leaves plenty of free time to do something on the side when you don’t have kids / a family to take care of
Show of hands: How many others feel this way?
Personally, I can barely muster the energy to do much hacking after a normal job. The only way I've found to do work I've been known for is by blowing off my other responsibilities (sometimes to the annoyance of various people).
I have also become known for what I do, in the last minutes of odd hours, to the neglect of my responsabilities. While I do "make time", and could probably do so more effectively[1], I certainly do not have "plenty" after 40 hours.
1: One needs downtime, and can't expect perfect utilization even after planning for rest.
So sounds like you are one of the lucky folks who is excited and really enjoying their day job that you dont need a challenge after work. I once heard that those who are very stimulated at work actually spend a lot of energy and need cool down "after work". I (like many I know) can't wait to get home after a soul crushing day (at a pretty well paying job) to work on exciting things! Depends on factors that energize and motivate you I guess!
There are also people who hate their day job, and after dealing with food, chores, and physical fitness, just want to spend their last waking hour or two relaxing before starting over.
That is unless you agreed to a contract that forbids from holding multiple jobs.
40h/week paying the bills leaves plenty of free time to do something on the side when you don’t have kids / a family to take care of