It’s now two days post Ironman. I’m in Kona, Hawaii, sitting in a beach restaurant at about mile one of the swim. I watched the sunset. I watched the couples enjoying dinner on the sand. I drank two exotic drinks. I hurt everywhere and can only walk a little. I need to share this experience.In 1978, I completed a marathon, thinking that was the human limit. Then I read in Sports Illustrated about some Navy Seals who argued among themselves about the greatest endurance challenge: biking, swimming, or running. After too many drinks, they designed a 140.6-mile race that encompassed all three. At the time, I didn’t really believe their Ironman was humanly possible. Two years later a 65-year-old man finished the race and the thought entered my head: Could I at 65? Would I?At age 65, I lined up at the start of the Coeur d’Alene Triathlon to find out. I was too slow in the swim and didn’t survive the 2:20 cutoff. I was disqualified, and I went home embarrassed. The next year, after swim lessons and 20 hours a week training, I went to St. George, Utah, to try again. I just hoped to make the cutoff times an …