The rules keep changing

Why do the French mess with me so? Part of the progress I feel like I've made here has been with knowing how things work. And then things go and change, e.g. last night at dinner. We ordered le menu which gives one a choice of appetizer, entree, and dessert. We know from previous experience that you order the app and entree at the start, and then when you've finished, they come round and ask for your dessert selection. At least, that's how it works everywhere but the place we ate last night. Luckily my French has improved enough for me to flag down the waitress (after we patiently waited 15 minutes for her to come see if we wanted anything) and ask if we could choose our dessert. She mumbled something, seeming annoyed that we wanted dessert . Oh well, not our problem I decided. We try to play by the rules, but they keep changing them.