Yeah…. You have to be really passionate about what you are going to do. I’ve seen some people do it to do a wholesale career change (lawyer turned teacher, etc.). The interesting thing is, I think in most instances, those who do that, do it for a period of time, knowing that they are already FI. It is truly a “fun hobby”.
I recall one time listening to Dave Ramsey and a fellow who was an engineer was really burned out. He said he wanted another job, and wanted to just go work at Wal-Mart or Target and earn $12/hr because he “didn’t need the money” and was burned out. Ramsey told him he was a lunatic and would despise that job. And, if I recall correctly, that he still needed to work.