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!