At 7:30, just as I delivered the first cup of coffee to the bedroom, the doorbell rang. Spouse looked alarmed and asked questions that were hard to answer. However, I speculated that the caller might have been one of her 7:30 clients arriving on the wrong day. Much quiet cursing followed this thought and spouse dashed about the room grabbing the minimal clothing that she could wear to the door to face a client.
By the time she opened the door, the caller had backed away and was digging in her backpack. She found her diary, looked at it, turned to spouse and said, "Oops, I'm supposed to be here next week." And off she went.
Spouse returned looking like thunder, threw her clothes on the floor and flounced back into the bed. By then the coffee was cooling. That seemed like a good moment for me to go out to the kitchen to make fresh coffee.
I guess people who need psychotherapy because their life is in chaos can be expected to make this kind of mistake, but some days it really would be great if they could look in their diaries before ringing the bell.