I've been doing Ashtanga yoga on and off for about 9 years and I still feel like a beginner. I think that is the key for me to really enjoying it. It's not about mastering a pose -- it's just about being in that class on that day. Honestly, on some days I can get into a great downward dog, do a really smooth vinysa, and hold a balance pose really well; and on others I am stiff as a board and can't even start a balance pose. Each class and each day is totally different. I will be a beginner at yoga for the rest of my life, and I want it that way.