Why this pose is really my favourite pose is because it seems as if it is the easiest pose amidst the various more complicated asanas that one could be in. Yet, it is deceptively simple.
I love it because it represents the culmination of a well-done practice and a means of gifting my body and mind with rest. Too often, we often think of offering gratitude in terms of physical gifts or items and often to an external recipient, but hardly to ourselves.
It is also deceptively simple because it can be very difficult to actually quieten and focus the mind while in this pose. Usually within a minute or two, the mind starts wandering on to what one should next do after practice, or recollect the past. It is far harder to remain focused on the present and be in the present.
This pose is thus my favourite because it reminds me first of being kind to my body and mind, and secondly to focus on the here and now.
However, with that being said, I am in the gradual process right now of considering shirshsana as my favourite. I never dared to do it before due to really extreme fear. However, it was during the TTC that I went up in my first headstand, albeit wall-supported.
It represents to me a major step outside my comfort zone and having the courage to practice despite my extreme panic at times regarding this asana.