Oh no. Punch your brother in the gut for me. Or a light jab. Or something. I know how it feels to have all your work gone in a flash like that, even if it's just something done in a video game.
I once was trying to get a surfing Pikachu back in the day. It was something ridiculously hard like defeat the hardest stadium in Pokemon Stadium, using only Pokemon in your Pokemon Yellow game and Pikachu has to be on the team or something like that. I was training my team and SURPRISE! Parents are like vacation in Vietnam, let's go. So, no biggie, just train my team while I was there. Cousins got my game somehow, replaced my save game and all that work goooone. Just gone.
Too devastated to start over. And I don't even know where my game is now, or if the N64 and it's attachments still work.
Oh well, live and learn. Hanging on the edge of tomorrow