Yesterday, my sister, Carol and I hiked up to the top of Mt. Wilson. It's a climb of over 5,000 feet in 7 1/2 miles. It was hot and dusty and difficult. At one point I asked her when we would stop being compelled to do these hard physical feats. Her answer was short and simple: "when we're dead."
I believe she's right. I will be 60 in three years and feel I have many more difficult, challenging miles to conquer. Hurray for the wisdom that comes with aging.