I know it was some time in 2002. IDK what my first Linux distro was TBH, but I quickly returned to windows. Then Shortly after I took a dive off the deep end to try to really learn Linux some and spent days installing Gentoo on some probably 400-600 MHz single core box (was in college at the time). That, while being pretty painful overall, was a good learning experience. I was in school for computer aided drafting, got my associates, and here I am 20 years later as a DevOps engineer. I am comfortable with the big 3 OSes, tho mac would be my weakest. Gaming keeps bringing me back to a home Windows desktop, tho. Actually just set up a USB stick with nix plasma to check out this weekend as I think I'm missing the train on nix.
Edits: mostly spelling, originally posted on phone, typos galore