Brian put it into words much better than I could.
Ironman is just a triathlon. A long one, to be sure. Easier for some who are blessed with natural endurance, and harder for others who are not. The finish line is not a confirmation that you're a superior person. It's not achieving nirvana. It's not being named to the Supreme Court, or being knighted, or receiving a cardinal's hat. It doesn't make you a Nice Person or even one worthy of a huge amount of respect and admiration. It doesn't earn you a million dollars or a place among the stars. It's not a validation of your existence here on this earth.
It's not even essential for becoming a "Real Triathlete", whatever that is. It may be your own personal Mt. Everest, but you know what? It's not really climbing Mt. Everest (that is, at least not until ~50,000 people are summiting Everest every year). It's not discovering a cure for cancer, and it's not saving people from burning buildings, either.
It's a long triathlon that earns you a $5 medal at the finish line and the title "Ironman". That's pretty much IT!
That's enough for me! And if I cross that finish line next November, along with a couple thousand other folks, I'll thank the volunteers for being out there all day for us, and I'll be pleased and thankful that I was able to become fit enough to do it, and grateful that the support of my husband gave me enough free time (and financial wherewithal) to accomplish it. And then I'll be off to some other project and some other race.
But in the meantime, my readers are going to be slogging through the ten months of self-obsessed training that it will take to get this lazy old carcass ready for the starting line. Thanks for coming along for the ride!
If, after this year is done, and I achieve my goal, and I casually mention at a cocktail party that "By the way, did I happen to mention I'm an Ironman?" you all have permission to slap me.