I am no shiny hunter, but I have one memory that will forever haunt me.
I played the shit out of Pokémon diamond. Eventually, I got board and started using an action replay. I had many adventures that way by like, custom starters.
One day, I was lucky enough to take part of an official Darkrai event. I go to his island and somehow he was a shiny. I managed to catch him and it was an amazing experience.
It was also the same day I learnt the lesson of using the save feature asap. I can't remember what happened exactly, but I think I knocked the cartridge or something and crashed the came. My last save was right in front of Darkrai. I tried so hard to get him as a shiny again, but it never happened. It was devastating lmao