all I keep wondering is why I didn't try this sooner.
I think your experience is the most common way people first try Linux: most people first try Linux when they have a computer that is no longer valuable to them.
That was what happened to me. I had a Windows laptop that was running too slow for use, and a friend suggested setting up a Linux partition before I bought a new one. I did, and got another two years out of the laptop.
Now I see a lot of libraries and hackerspaces offering folks help doing this.