Ony of my colleagues remarked that every time he visits the dentist, the hygienist seems to have stalker-level knowledge of his life.
"How did your son do at the chess tournament?"
"Have you decided to do anything fun with your brother's family when they come to visit?"
"Did your wife's performance go well?"
Eventually, he realized why the hygienist knew so much about his life: Because his wife's dentist schedule matches his, but she goes in a month earlier.
The hygienist chats with his wife during her visit, which means that when he goes in a few weeks later, the hygienist asks follow-up questions.