Actually, I was logged in, had the events entered, and then hit "submit" at 4:00:01 (based on GenCon's count-down clock), and, well, the tabs crashed, I haven't gotten back to the registration page yet (much less had a chance to re-enter the 15 event numbers).
I agree, it is far better to be prepared - however, it is not a panacea.
I am NOT a civilized man.