Yes, flexibility of body and physical perfection for Yogasana is important. However more important is the state of your mind, Meditative mind. Your flexibility might be excellent but if your mind is not attentive, you are merely doing some physical exercise, not Yoga.
B.K.S. IyengarAll of us have a dormant spark of divinity in us which has to be fanned into flame by yoga.
B.K.S. IyengarAs a well cut diamond has many facets, each reflecting a different color of light, so does the word yoga, each facet reflecting a different shade of meaning and revealing different aspects of the entire range of human endeavor to win inner peace and happiness.
B.K.S. Iyengar