> The point where I really feel the difference is that Western Zen seems to be about how to train the self to become stronger, whereas actual Seon (Zen) in East Asia is about going with nature, letting go of the self, and allowing things to flow.

I think the Western sentiment, and why it is attached to strength, comes from a combination of the West's allure to Eastern martial arts and the reality of plateauing during training. Once you've been doing something for 2 years, you are no longer seeing the massive learning gains you saw as a true novice. However in that journey toward "mastery" (a term I hate) you have to keep a positive outlook that the practice takes time.

I now use this phrase from my instructor: "Practice makes permanent". There's no such thing as "perfect practice", but whatever you practice is what will stick.