When preparing to go out to a restaurant, some people check out the menu or figure out where they're going to park in order to make the dining experience more enjoyable. Chronically anxious people who overthink everything will take things 10 steps further by not only choosing the meal they'll order, but reciting in their head how they'll tell the waitress. Not only will they find parking, but they'll book in advance with the valet so they don't stress about spots being all taken by the time they arrive. Anxious people will overthink just about every human interaction that could possibly occur in their time at out in public and there's no amount of therapy that could cure the overthinking.
The only thing to do about it is take a quick LOL with your therapist and get your next reservation. For last week's batch of highly anxious hilarity, check out these anxiety memes to snicker at for a little longer.