I had joined the Games Workshop fandom at the tail end of 9th edition. I started out learning standard Warhammer 40k and ended up choosing the Black Templars as my army. While attempting to learn that, I was shown Kill Team which of course I also bought a rule book for and tried to learn. Around this time I discovered they had a whole nother game called Age Of Sigmar with even more armies and so I had to check that out. Then they hit me with Boarding Actions and finally 10th edition. I think I blew some sort of fuse in my brain at that point and had to check out of all of it. I never really felt like I had a firm grasp of the rules for any of those games. It was just too much too quickly.
