As the ticket agent at the airline check-in counter hands you your boarding pass and points you to your departure gate, he says that he will call the agent at the gate to try to get you upgraded. He doesn’t.

As the flight attendant hands you your box lunch, she says that she will come right back with your special request for non-fat milk. She doesn’t.

As the rental car agent hands you your contract, he says that he will call ahead to the dispatching area to see if he can fulfill your request for a domestic model. He doesn’t.

As the clerk at the hotel check-in desk hands you your room key and directs you to the elevators, she says that she will call housekeeping to deliver an extra blanket to your room. She doesn’t.

As the waiter hands you your paid receipt for dinner, he says that he will return to warm up your coffee. He doesn’t.

What’s going on here? Is there a conspiracy among service providers to withhold service from you? Do these people have it in for you?

Well before you go getting all paranoid, it’s probably not about you at all. It’s most likely about them. These people are probably just succumbing to a psychological phenomenon called the Zeigarnik Effect. The Zeig… what?

Okay, a little background (or so the story goes): While sitting in a restaurant in Vienna—every good story about a psychologist takes place in Vienna—Bluma Zeigarnik noticed that a waiter could remember a seemingly endless number of items that had been ordered by his customers. However, once he had delivered the orders to the waiting diners, he no longer remembered what he had just served.

What Zeigarnik had witnessed was the fact that people remember the particulars of incomplete tasks, but once they complete that task, they forget about it and about its associated odds and ends. In the case of Zeigarnik’s waiter, after delivering the orders to his patrons, he forgot about the orders—and often the patrons who had placed them.

Though Zeigarnik didn’t get her coffee cup refilled following her meal, she did get into the annals of psychology. Zeigarnik theorized that an incomplete task or unfinished business creates “psychic tension” within us. This tension acts as a motivator to drive us toward completing the task or finishing the business. In Gestalt terms, we are motivated to seek “closure.” (How often do we here that from psychologists?) Then, once completed or finished, the tension dissipates and we move on to other open issues.

So how does the Zeigarnik Effect affect you? Simple. Don’t allow a service transaction to be completed until you receive the service you request.

Don’t take your ticket from the agent at the airline check-in counter until he calls the gate agent regarding your upgrade.

Don’t let the flight attendant leave until she activates the call button at your seat as a reminder to return with your non-fat milk.

Don’t accept the contract from the rental car agent until he calls the dispatch area regarding your request for a domestic model.

Don’t take your room key from the check-in clerk at the hotel until she calls housekeeping for an additional blanket. And as Zeigarnik herself discovered, don’t pay your bill until you’ve been served the last of your after-dinner coffee. Otherwise, as they probably don’t say in Vienna, “Fugedaboudit.”