Ever wonder why at the end of savasana we roll to the right to sit upright? Me too.
After looking into it, I found that the main reason we roll to the right is to put less pressure on our heart, which lies on our left side of our body. This way it is above the rest of our organs as we come out of corpse pose, leaving it rested and open.
Another theory of why we roll right, is that the parasympathetic (relaxation response) nervous system is primarily associated with the left, whereas the sympathetic (active response) nervous system is associated with the right. When we roll to the right it activates the right (sympathetic) side more, causing wakefulness as we come out of our relaxed state.