I don't know how (specifically) I found PGC, but I did, and created an account back in 2013. I can tell you how I found BGC today, though. I was looking to see if I was the first person to dump the boot ROM of the Kong Feng GB Boy Colour, which is a Gameboy clone. I found a post requesting the boot ROM here. When I went to register an account I found out my name was already registered.

Curiously though, the forums seems to think I had posted once before, although I can't see this post. Either this is some glitch, or I have an old post that's been moved to a hidden forum section. Intriguing!