Come on there must be things that drive you nuts. Here's my two.

Enormous kids and by enormous I mean age wise, being crammed into those Disney strollers. We saw loads that were easily 8/9 if they were a day. They must have needed a shoe horn to get them out! A lot of them couldn't even fit their legs in.

The second one an adult reserving a place in a queue then the rest of the group arriving later. Have no problems with leaving a line to take kids to the toilet have done it myself loads of times.[msnembarrased]but I always make sure everyone knows I am doing it.