To learn a new skill like fighting with a knife or defending yourself against an attacker you will need to practice certain movements slowly and then faster and then under pressure but still resulting in the capability of responding effectively. It often involves improving the smoothness and accuracy of movements and is obviously necessary for complicated movements; but it is also important for calibrating simple movements like reflexes, as parameters of the body and environment change.
Knife skills already learned and sensitivity of error-detection and strength of movement plays a role. Repetitive learning is “relatively permanent”, as the capability to respond appropriately is acquired and retained. As a result, … If you give the knife back to you attacker every time, after disarming him- you might just do the same one day while being attacked for real. (You gave the knife back to your training partner after every movement to practice again)!?
The processes that affect behavior during practice should be considered for optimal information retention.