Arrest records question???

So when I was 13 and living in North Carolina I went to juvenile detention for simple assault (fight in school) and failed drug test in court cause I was being a hooligan smoking pot with the other hooligans πŸ˜‚πŸ˜‚ but anyways my arrest record got expunged when I turned 18 now when you look up my arrests I’m clean . But my fiancΓ© still has his juvenile charges and they hold his against him for anything he gets in trouble for weather it’s a simple ticket or misdemeanor, his juvenile charges are in Florida. Does anyone know why mine are expunged but his are still coming back to haunt him ??

Edit: thanks for reminding me of my illiteracy πŸ˜‚πŸ˜‚πŸ˜‚ seriously beating myself up over the word expunged I seriously thought it was exsponged cause it sounds like that and I never seen it spelt πŸ˜‚πŸ˜‚πŸ˜‚πŸ˜‚