There is often a wait associated with common errand locations: the post office, the bank, the grocery. In anticipation of having to wait, people entering these premises allocate themselves an amount of patience. Allocating patience is like cocking a gun; the patience should be discharged before too long. Most people discharge their patience in small bursts which surface to the outside world as audible sighing, clearing of throat, or shifting of weight from one foot to the other.

The people in these situations are at risk of running into two types of problems which jeopardize successful completion of their errand:

1. Considering their average rate of patience discharge and the duration of their wait, their initial patience allocation was insufficient.

2. Rather than small, periodic bursts, they discharge their patience climatically all in one go like Mount St. Helens.

There are two types of people who experience problem #1: passive and active. When passive people have spent all their patience, they bow their heads, mutter a word of frustration, sacrifice their place in line, and return to their car, defeated. When active people sense that their patience reserve is running low, they opt to additionally get themselves into problem #2 and discharge their remaining patience in a big bang.

The difference in end result between problems 1 and 2 is that for people who remain in problem 1, their failure to complete the errand is self-imposed, whereas for people who migrate from problem 1 to problem 2 (or were only ever in problem 2), their failure to complete the errand is a consequence of denial of service on behalf of employees, who refuse to assist people who behave threateningly.