It’s been a revelation for me to read that Kobun Chino Otogawa started sitting the lotus at age 7, wrestled in the lotus with his brothers, and could get in and out of the lotus without using his hands. Of course, his father was the abbot of a Zen temple in Japan.
At the close of a sesshin I attended, Kobun said it was his third sesshin in a row, and when asked he said he didn’t experience pain in the lotus. In fact, in what I read, he said he sat the lotus to stay out of pain!
All these years I’ve kept his instruction to “take your time with the lotus” in mind, ever since I heard him give that advice in the early ’70’s. I continue to do so, and to regard the lotus as my teacher.
My posture is not good, Zen teachers can barely keep their hands off me when I go to sesshin (sounds like the same is true for American Zen priests who go to Japan, even if they have good posture).
The job here in the West, as far as I’m concerned, is to understand the causality, physical and mental, behind the action of the posture and the mind, accept it and let it play out. If I sit up straight some of the time, it’s not because I’m trying to sit up straight.