Relaxing the Grip in the Framework of Tradition

So I read this from Pema Chodron's book "When Things Fall Apart"...
"In his own way, Trungpa Rinpoche devised such a course for his students. He'd have us memorize certain chants, and a few moths after most of us knew them, he'd change the wording. He'd teach us specific rituals and be extremely precise about how they should be done. Just about the time we began criticizing people who did them wrong, he'd teach the rituals in a completely different way. After years of this sort of training, one begins to relax one's grip."

After reading this, my first thought was "Ah, that's just like Ashtanga yoga!" My second thought was " Wow, I still have a lot of work to do as far as "relaxing the grip"! I like structure and routine. It gives a certain amount of background familiarity to the chaos of everyday life. I generally don't like surprises, even the good ones. I like time to mull over and prepare for what's coming next.

When I started an Ashtanga yoga practice, I thought it was great. We do the same poses in the same order every day. There is a system and an order. It only took a short amount of regular practice to discover that while we may do triangle pose or a standing forward bend everyday, it is never the same triangle pose or forward bend twice. No two practices are ever the same.

I often have the feeling that my teacher is watching my practice for those places where I'm just a little too comfortable. It seems to be just that moment when he appears next to me asking me to change some aspect of a pose. Almost always the first sensation that I notice is mental resistance. I don't want to change it. What I'm doing now is comfortable and familiar. So the work in practice for me is often to "relax the grip". I think because Ashtanga yoga provides such a precise structure I have been able to begin the work of relaxing my grip on "how things should be". It has made all the difference for me to have the structure to push against.