This video may be old but its message is timeless.
(it was created in 1999, the year I was discharged)
Being a marksman is a vital skill for preparedness. Ammunition is only going to become more expensive and harder to find. The day is looming that ammunition will be registered or otherwise strictly controlled.
Being able to get rounds on target quickly and efficiently without waste is a key skill.
In my years as a firearm instructor I have learned that marksmanship is partly knowledge (knowledge that is found in the great video below.) but is also the willingness to apply that knowledge and the discipline to practice when it is not convenient, easy, or fun.
I learned to shoot a rifle in the Marines, and while I am rusty, some things are never forgot.
Due to the quality of Marine Corps rifle training, I can pick up a rifle and remember the hours spent aiming at the white drum pained with targets. One thing the Marine Corps does well is make riflemen out of teenagers.