You have to look happy all the time and that's a big strain. You have to look happy, but concerned, bending forward while they talk, listening carefully, asking: ranch or thousand island? You have to act like you believe in yourself. You know what you're doing. Everything is going according to a plan that you know about, even if it isn't apparent to them. You can't think of all the things going wrong in the kitchen.
You have to remember: gin and tonic to Table 8; fish bone in the throat Table 3; man at 12 late for a meeting; nut allergy on 5. You have to remember it all and not get bogged down.
Each table is a clean slate and a chance for things to go right. You can't think of what you've done wrong, what you might do wrong, what you might forget, all the mistakes you've made or could make. You've got to have a clear mind.
You have to time the food so no one has to wait too long, but they don't have to hurry up either. You have to get the right food to the right people and you can't spill or drop any plates and you have to remember to give everybody coffee and ketchup and tabasco and all the things they forgot to ask for the first time, when you were writing it down.