I used to count shots because of shooting a 1911, SA & DA revolvers. Then, after I became a LE firearms instructor, I was always counting shots when our qual scenarios involved firing a specific number of shots, both for myself ... and when qualifying/observing other shooters.
Not being able to show attention to following even simple instructions in a range environment, meaning something as simple as only shooting x-number of rounds at x-number of different targets, can show either a lack of listening to instructions in the first place
... or being unable to remember instructions when having to multitask on a range.
Then, add in some requirements to exercise simple Judgment tasks, meaning shoot/no-shoot situations and targets, while having to assess and decide on-the-go, and that can really start testing the abilities of folks to recognize, orient and think on their feet while deciding if they should act ... and how to act.
Bottom line? Even when I don't consciously think to listen and count rounds, more often than not some part of my subconscious is apparently counting shots heard, whether mine or those of someone else to whom I'm paying attention. It was the years of serving as a firearms trainer that really seemed to cement the habit.
Not being able to show attention to following even simple instructions in a range environment, meaning something as simple as only shooting x-number of rounds at x-number of different targets, can show either a lack of listening to instructions in the first place


Then, add in some requirements to exercise simple Judgment tasks, meaning shoot/no-shoot situations and targets, while having to assess and decide on-the-go, and that can really start testing the abilities of folks to recognize, orient and think on their feet while deciding if they should act ... and how to act.

Bottom line? Even when I don't consciously think to listen and count rounds, more often than not some part of my subconscious is apparently counting shots heard, whether mine or those of someone else to whom I'm paying attention. It was the years of serving as a firearms trainer that really seemed to cement the habit.