If I never explore my limits, my bodymind will gradually tighten and become unconscious. If I regularly explore my limits in a caring and adventuresome fashion, I will expand and grow in a vital fashion. But if I try to push myself past where I am honestly able to go, I will no longer be practicing yoga but instead will be practicing greed, and I will probably be met by pain and disease. Stated simply, it is the difference between ignoring your self, making love to yourself, and raping yourself.
