Same here. I pre-reg at Kumoricon every year for Sakuracon, that way I don't have to worry about it. Sometimes though, I'll forget and go "Oh ----! I don't have any money to register for Sakuracon!" But then I remember that I registered back when I DID have money. My only problem is hotel. I don't need to eat anything.
I have a room reserved, too that I forget about. I am on top of this.