My first shiny is a bit different to just about everyone else's. During my first ever run through of Silver, I traded a Bellsprout for an shiny Onix with that guy in Violet City. Since I had never encountered anything like this before, I had no idea what was wrong with the Onix so I thought that it had been corrupted. As a result, I put it in my PC and never let it see the light of day again.
Now that I know what shinies are, I would have cared for that Onix if I could do it all over again D: