Yoga is not about flexibility or strength which is what most people understand about Yoga. Yoga is about peace and freedom. By being caught up in the pursuit of flexibility and strength we direct our energies in a goal which involves accumulation. And everyone knows that there is no limit to how much one can want. Than the pursuit of power, wealth are a similar attraction without end. Therefore we must devote our time to renunciation - which is surrender - rather than accumulation. For most of us the giving up of things is a threat to social norm.