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

People say that steadiness of mind is an end; no, it is a beginning. I am there; I can explain everything up to that point. Then I struggle to discover what comes after, so this steadiness is not an end, it is the beginning and the instrument.

You exist without the feeling of existence.

Yoga is a way of life; it is an art, a science, a philosophy.

Life without tapas, is like a heart without love.

As a mighty river which when properly harnessed by dams and canals, creates a vast reservoir of water, prevents famine and provides abundant power for industry; so also the mind, when controlled, provides a reservoir of peace and generates abundant energy for the human uplift.

As long as you do not feel the serenity in the body, in each and every joint, there is no chance for emancipation. You are in bondage. So while you are sweating and aching, let your heart be light and let it fill your body with gladness. You are not only becoming free, but you are also being free. What is not to be glad about? The pain is temporary. The freedom is permanent.