How do you like how your body works? I mean, when you go to step on an ant or use your foot to close a door; do you like how it works? How do you like how your body works when you reach for the shave cream in the morning, or to pick up a pen on the desk? How do you like it when you point at something and you are actually pointing at that something?
Having a gun, fit, is akin to having it be a part of your body; not the guy next to you, or the guy next to him, but your body, your body parts.
If you like how your body parts work together in the types of movements/ activities above, then it is as relevant as having YOUR body parts, not someone else's which you are trying to function and move with.
