You will need a four inch roller for this lesson during the variations that involve kneeling. For those who have trouble with their knees that prevent kneeling, you can do this on a meditation cushion (or any 4"cushion) with legs extended, heels contacting the floor. Have you an understanding of how to live the way you want to live? Where is the line between doing what you "should" do and doing what you want to do? Most people stop growing when they become an adult. Is that good enough now, during these times of challenge and the increased necessity to adapt to ever-changing scenarios?