When I first started teaching, almost no child could do this pose with stillness. They have learnt that as we grow up, one of the hardest things is to know when to rest and relax and when to work and act. They have understood that if we forget the importance of rest and conscious relaxation (where you are not sleeping), you will have the energy and clarity to do more and illness. Pls do note that they have done a myriad of poses up and down, stretched and strengthened, twisted and jumped… and finally we conclude with this. That is why (among other reasons) savasana is called the most important pose.