Generally, there are three things that you can do when an emergency rears its ugly head: you can run away and hope that the situation is better somewhere else, you can fight and hope to defeat whatever the problem is, or you can hide out and hope that the situation ends up resolving itself with time.  Now, there are going to be some cases when any kind of plan can work- there is no ultimately worthless strategy, if you examine enough obscure possibilities.  So let’s take a brief look at one possible scenario which could make any one of these three strategies useful.
You can run from just about anything.  Of course, if you end up running from something that is faster than you (such as a bull or a car), you will likely find that your options are limited to being badly injured or killed.  However, you might be able to run from a burglar who breaks into your home, or a thug on the street who wants what you are carrying.

Fighting is usually not a good idea unless you have a competitive advantage such as a gun.  With guns, all things are possible, provided you shoot first and shoot accurately.  When you fight, the idea is to carefully assess what your opponent can attack you with, and attack them with something worse before they have a chance to hit you with their best possible attack.  Do you have the atomic bomb, or will you resort to desperate tactics like having teenage pilots fly their planes directly into the enemy?

Hiding is a great strategy, especially if you want to act like a rodent.  If there are no reasonable avenues for escape, and you are fairly certain that your opponent would destroy you, sometimes it is best to simply lurk in the shadows and wait out the situation.  While this is not generally a brave option, often a coward lives a bit longer.