Related:

• Matter cannot be created or destroyed, nor can it be returned without a receipt.
• Just as there are laws of Conservation of Matter and Energy, so there are in fact Laws of Conservation of Pain and Joy.
  Neither can ever be created or destroyed. But one can be converted into the other....
• Life can not be created or destroyed, it can only be screwed up.
• Anvari's Law of Homework: A homework doesn't get created or destroyed, but can be converted from one form to another.
• To let understanding stop at what can be understood is a high attainment.
  Those who cannot do it will be destroyed on the lathe of heaven. -- Chuang Tse XXIII...