Sicario2 - Tier 1 what do you mean 'before' us? We won an FA Cup four years ago, so how far do we go back (rhetorical question if that wasn't apparent)?
If any United fan tried to claim they had bragging rights, I think I'd find it very easy to shut that chat down.
Bottom line - yes, we need to win trophies some time soon but if you're feeling insecure because United have won the cup today, then I don't think you're looking at the bigger picture/need to have more pride in what we've achieved & where we're headed. An FA Cup or not doesn't really change that.