When things start to get off the prescribed level of "rightness" our alertness goes up and we start looking for the [un]usual and details to help us explain the situation or look for danger.
Lima is correct - and of course this makes perfect sense. You do not walk around taking exact note of everything around you, memorizing what every person is wearing, as if at any moment you're going to be asked to do one of those "spot the differences" tests.
Your concentration and focus are finite quantities, requiring large amounts of glucose, and so our brains have evolved to be highly efficient. We learn to use patterns such that we can push non-essential activity off to the level of scripts. As an example, consider paying for something in a convenience store. Usually, what's important is speed. You focus on completing the transaction quickly.
During the payment sequence, if someone surreptitiously switches clerks on you, so what?
This is
all about SA. Consider the basketball-gorilla video. The trick involves the setup. You are told to "count the number of passes." As a result, you put all of your processing power on that task. If you're sharp, you'll get the number correctly (and probably miss the gorilla). Magicians rely on misdirection like this to perform their illusions.
But what if the task is different? Sit someone down in front of that video and tell them, "watch for anything unusual." They'll spot the gorilla straightaway.
In a similar way, when you're walking back to your car in a parking lot at night, your task is not, "count the number of cars and memorize the makes and models," no, your task is "be alert to the possibility of danger and watch for anything unusual." That's where you should be putting your attention.
Good SA, in this scenario, is using your eyes and ears. It's picking a path that avoids traps and blindspots, thinking like a predator and avoiding simple mistakes.
I'm going into detail on this because many people do not understand what good SA is. I guarantee that right now, someone is reading this and getting ready to pen an angry response:
"No, you wrong. I see everything. I memorize the license plate of every car I walk past. I memorize the position of every telephone pole and blah blah blah." And of course they don't.
If you waste your concentration and resources on needless tasks, you'll have less chance to spot the really important things. Good SA is selective attention - it's knowing what to focus on and how to scan. It adapts to circumstance and threat level, per
Cooper's color scale.
Yes, OKShooter is correct: As long as your firearm is reasonably concealed, and you do not act suspicious and
draw attention to yourself, nobody is likely to notice.
That means that you have to perform your end of the script, and behave like a "person not carrying a gun." If you're nervous, sweating, looking around, tugging at your shirt tail, patting your gun, etc., then you'll look out of place and unusual and increase the odds of "being made."