At the age of 45, most days in Tucson were spent feeling like I was on the summit of Mauna Kea, as I was exhibiting debilitating health symptoms that corresponded to what I saw at very high altitude. I was later to find that I had erratic low blood oxygen levels after almost a decade of high altitude work.
The Coin of Life example: Say you have a coin with heads on one side and tails on the other side. One side would mean good and the other bad, based on your interpretation or bet of which side of the coin represents a win for you. However, you can't decide the outcome and the coin flips many times throughout your life. Finding balance is flipping the coin in such a way that neither of the sides is of greater importance to you, but if the coin lands on the middle bit, you realize that the space between what you consider good or bad is so small and the probability of landing there is also incredibly small without continuous practice. However, no matter the outcome, you choose to accept the coin as it is, with both sides, and appreciate the importance of both in your life. For the coin of life has meaning and value no matter what side it lands on. It's each individual's choice whether to bet on the outcome or not, but ultimately your coin of life will be spent somehow.
I consider myself fortunate that I spent three years working at 7,775 feet before spending five years working at 13,796 feet on the summit of Mauna Kea. I can only wonder how much more severe my long term very high altitude sickness could have been without the initial adaptation to the lower altitude.