One question I asked him was: In the past 15 years, since I studied with you full time, what is the biggest mistake you have made in your training?
He answered that although there were probably 200 or so small errors, the biggest problem was not having an outside eye to correct him. Had other teachers been willing to offer helpful corrections, and constructive criticism, he could have saved a lot of time--and the art of Taijiquan itself would have been furthered.
He says that when he offers helpful criticism to other teachers they don't want to hear it, they see criticism as a challenge to fight, not as a way to further the art.
In essence, his challenge to us is to create a taijiquan culture of helpful criticism.
Youtube video exchanges/debates are a fun place to start and I really hope to see more of them, but we're really talking about understanding Taijiquan as an ART not just a fighting system. When we view it as an art, we can all take pleasure in our personal contribution, but we can also take pleasure in the furthering of the ART as a whole.
I would love it if a few people would post comments about the biggest mistakes they have made in their training, for everyone else's benefit.