Culinary is the worst kind of guessing

This happens to me. You're at a restaurant and you see someone enjoying a dish that looks right up your alley. You look over the menu and -- by way of your powers of deductive reasoning -- you determine which menu item it is and assure yourself that you will order that thing when you come back the next time. But when you next dine, you order the item you thought it was, and it turns out to be something entirely -- and disappointingly -- different. And you carefully go over the menu and still think that there is nothing else it could possibly be. And it occurs to you that you observed someone who has a special relationship with the chef and can order something that isn't on the menu at all. This is more prone to happen in a Chinese restaurant, I find.

West Lake Beef Soup, my eye.