When the hunter Van Pelt runs out of shells for his rifle, he goes to a nearby gun shop. After Van Pelt buys a new rifle, the shopkeeper asks the hunter a strange question:
“You’re not a postal worker, are you?”
This seems like a particularly strange question to ask someone after selling them a gun.
Why did the gun salesman ask if Van Pelt was a postal worker?
Back in the 70s and early/mid 80s, there were a few incidents of workplace violence here in the US, and the workplace happened to be the local postal system. Since then, "going postal" has been a "thing" to reference.
The expression derives from a series of incidents from 1986 onward in which United States Postal Service (USPS) workers shot and killed managers, fellow workers, and members of the police or general public in acts of mass murder. Between 1970 and 1997, more than 40 people were killed by current or former employees in at least 20 incidents of workplace rage.
This is a reference to going postal, an American idiom for becoming so enraged that one procures a firearm, and returns to one's (possibly former) workplace to shoot a lot of people. The term comes from America's history in the 1970s through 1990s, when dozens of such events—about 8 of which involved then current or former postal employees—occurred.
