LOL! Early on I had some unexpected luck selling some of my domains for low-ish thousand of dollars. That encouraged me to kinda just buy domains when I have an idea or stumble on a thing that I believe I might do some day or let someone do some day.

For example, I sold hackathon.co for good money (I even gave them the GSuite at that time). I also sold html5.in to Microsoft sub $10,000 (via a broker, unfortunately, which I realized way later) still for a pretty good sum. I have also sold quite a few more for low $100s.

And I donated thus.org to a Texas university for zero dollar and gave them the GSuite too. I'm happy that an educational institute is using it and the domain is alive.

I own nsfw.in, which was "a link shortener to warn you that it might not be Safe before opening". I got lazy and is on sale and I keep getting regular emails/contacts to buy it.

Very cool, you sound like a resourceful person!