Perhaps what lies behind that statement is the perception that yoga is pretzel poses that only contortionists can do. In fact, such poses are not part of the ancient tradition of yoga, and if one wants to better understand the history of yoga and its relationship to Western women's gymnastics, I highly recommend "Yoga Body" by Mark Singleton. Ancient yogic texts actually refer to only a few postures, intended for people to build strength and stamina to sit and meditate for long periods of time.
The term "yoga" means different things to different people. The physical practice (referred to as "asana" which means "seat") is one of eight limbs of the spiritual practice of yoga. And yet to many, the term "yoga" is commonly associated with the physical practice. Now there is a growing community of teachers and practitioners specializing in the discipline of yoga therapy. While the definition of yoga therapy continues to evolve, to me it represents the integration of traditional yogic concepts and techniques with Western medical, physiological, and psychological knowledge. In this emerging tradition, there is recognition of the human being as an integrated mind-body system, and yogic techniques are used both as preventative measures to keep the body functioning optimally as well as to treat spiritual, physical, or mental ailments.
With these perspectives, what exactly does it mean to be "good" at yoga? There is no "good" or "bad", no judgment to be made. In yoga, there are just three rules to guide the practice:
- Start where you are. It doesn't matter how flexible you are or whether you are or are not flexible. If you can breathe, you can do yoga. There is always something for everyone to do, and there is always somewhere to go, more to learn.
- Join movement and breath. There is no posture without breath.
- Observe yourself. Through self-study and observation we gain awareness and presence of mind. We notice changes over time, understand cause-effect, and use that feedback to inform the future.
Ultimately the comment "I'm not good at yoga" comes down to ego. Just making it to the mat requires surrender and letting go of the inner critic that judges oneself and worries about being judged by others. And that is what yoga is about. (As an aside, this is also a necessary step for any creative endeavor!)