It's also a great quote, but it's a different one. "No battle plan survives contact with the enemy" is more like you get punched as much and in a way that you didn't expect, even if you planned to get punched. Tyson's saying "When you get punched the sensation is so unexpected that your brain stops working for some time". The 'counter' to the changing environment quote is to be flexible from the beginning. The 'counter' to Tyson's situation is to train so much, that your muscle memory will continue to work even if your brain doesn't.
> your muscle memory will continue to work even if your brain doesn't
Indeed, it is only when you encounter an actual combat situation that you understand why the karate elders insist on so many thousand mindless repetitions of basic movements back & forth: even though you have no time to think (and even if you did it would do no good because combat stress reduces your intellectual capacity by 80%), it instantly executes spontaneously and afterwards you find yourself thinking "wow - I did that ?". Brutal repetitive training that focuses on the basics: it works.
I feel like the there is something similar at play in long distance running. By repeating the same motion a lot, your nervous system probably works out the most efficient pathways to activate and can work without your conscious mind getting too involved.
