For every occupation, there is a catalog of secrets only its employees are aware of—such as how waiters with heavy platters know to look straight ahead, and never down. Armed with a bag of reader mail, Matthew Baldwin unfurls a whole lot more true insider knowledge.

Nurse

Patients will occasionally pretend to be unconscious. A surefire way to find them out is to pick up their hand, hold it above their face, and let go. If they smack themselves, they’re most likely unconscious; if not, they’re faking.

Technical Support

When helping someone fix their computer over the phone, and you want them to see if all the cables are plugged in correctly, don’t ask, “Have you checked to see if the cable is plugged in?” because the customer will always say, “Of course I did, do you think I’m a moron?” Instead say, “Remove the cable, blow the dust out of the connector, and plug it back in.” The customer will most likely reply, “Hey, it’s working now—I guess that dust really builds up in there!”