It could be that the reason for learning Yoga, like being able to touch our toes for example, grows to be completely different in a few months or years; just like we evolve constantly, so is Yoga and what Yoga was for me yesterday, might not mean the same today. Improvement is not always a straight line or clearly defined; often, the smaller, more subtle things are the real clues of our development or progress, maybe the quality of our breath, the posture of our backs or the capacity to listen more.