Hi Julie, thanks for your perspective. I have been given several explainations, one being that the Buddha finished his last teaching by showing his own physiological impermanence by passing away into Nirvana, while leaving behind his spiritual essence or spiritual life force in order to prolong his teaching.I can except that explaination, but why at the particular age of eighty, why not eighty one or eighty two? what do you think about the above explaination.