A few years ago, I met guy in my travels who seemed quite carefree and just enjoying frequent international travel with his spouse, funding various art initiati

A few years ago, I met guy in my travels who seemed quite carefree and just enjoying frequent international travel with his spouse, funding various art initiatives, etc. Turns out he wrote some utility-related software for a large American city back in the 80s and has nice a recurring revenue stream from that. Other than some now very occasional support requirements, it's essentially just a source of passive income. He said switching costs would be too great, and there's no need to change something that's working.