Bullet is an exceptionally hard game.

Bullet is a hard game. You rack your brains to think of the best move while the clock is ticking. You have this intense pressure that you're going to lose on time- so you just play a absolutely dumb move and just blunder. I think it requires a lot of brain power and most of the games I play always end in checkmate or timeout. 1000+ ELO in bullet is an incredible achievement.