Savasana, if done correctly, might be one of the hardest poses to achieve. It requires stillness of the senses, the body and the mind, while maintaining the 'intellect alert'. While you are in Savasana I read a beautiful text from the book "Light on Pranayama" by B.K.S. Iyengar, which talks about the true Self, the Atman, and also introduces the concept of the Koshas, or layers of the subtle body. This is why I chose to make this a level 3 practice for more seasoned practitioners for whom the concepts of Atman, Conciousness and Koshas might mean something. But of course, feel free to just listen to it as a curious beginner.