Final Subject Area: The Environmentby DA Caravella on 04/12/20
The three subject areas about which all judgments are made and actions are taken are yourself, the weapon (firearm), and the environment. One must analyze the environmental advantages and disadvantages presented in a self-defense situation. One might call this analysis of environmental conditions "situational awareness," which is ongoing and requires "repeated reviewing."
Conditions, such as the background behind the threat, can dramatically alter judgments and actions. Your own physical and mental ability may also be changing during a self-defense situation. Conditions change, hence situational awareness (analysis of the environment) is dynamic and requires the repeated review of conditions, i.e., taking advantage of changing conditions that can lead to survival.
This mental process of environmental awareness should be at the level of "automatic reaction," as opposed to "problem solving." This requires practice and training. An example: consider that you're writing your signature--this is action at the automatic reaction level (a complex activity done without much conscious thought). But now put the pen in your other hand and make your signature. This becomes an activity requiring much concentration and is at the problem solving level of accomplishment. With practice this can become an automatic reaction.
A final thought: the more your judgment and action can be "automatic," the more mental capacity you have available for situational awareness.