“The trained man (or woman) wins!”
I don’t remember where I first saw that, but it is something to think about. If you don’t train, how will you know what to do in a life and death confrontation? You might come up with a solution, but you’ll be behind the curve of the one who is trained.
Remember the OODA Loop (Observe, Orient, Decide, Act)? If you are in a situation you haven’t trained for, you run the risk of being stuck in the Decide part of the loop, and your opponent may be Acting while you are Deciding.