Sirsasana the king of all asanas and the reasons are not hard to find.

Awareness must be like the rays of the sun: extending everywhere, illuminating all.

There must be relaxation in full extension.

To do is hard, but to teach is still harder. Do not teach only to teach. Teach to improve the pupil. To be a teacher requires tremendous, vigorous discipline on oneself. We are teachers because somebody demands it from us. But the teacher should first rub his own self, and teach afterwards

There is a universal reality in ourselves that aligns us with a universal reality that is everywhere.

If you can adapt to and balance in a world that is always moving and unstable, you learn how to become tolerant to the permanence of change and difference.

I also say with backbends, you have to be cautiously bold. Not carelessly bold. You have to descend to the dictation of the spine. You cannot command from the brain to do the poses. As you play with a child, guarding the child from injuries, similarly you have to play in backbends, guarding your spine.