People who have actually experienced combat will tell you that it affects in different ways, depending on a lot of psychological mechanisms that are unique to each person and experience.
Your street experience must have been pretty sedate. Where I worked for many years I was in pursuits almost nightly, shot at frequently, in fights almost daily, running from robbery to shooting, to stabbing 12-15 times a shift.For myself, I always felt like everything I did after that was a joke. The street experience just did not cause me any great deal of alarm or concern.
The whole point of the Murphy reference was to never assume, violent attacks happen regardless of statistics.Mr Murphy? I said screw you a long time ago. What’s going to happen is going to happen.
You are right, no one else has ever been there.Others though, may have had experiences that triggered them in another direction; hyper awareness, or even constant paranoia that is debilitating.
Everyone is different, and you have to have been there to really comprehend that.