Well, you should know it's not something I do, it's something I DID. I don't run 62 miles every day, but I did once.
Though it's not as fun as the Ventures Xmas album, I think nearly anyone with enough drive can run an ultramarathon/ train for an Ironman. I was a drunk, ran 4.5 miles one day and found out I could run, then worked my way up to doing 62 miles. You should check out a coupla sources to help you on your way:
my story, The Long Run. Yes, I'm plugging my own writing. Relax, it's two bucks: http://www.amazon.com/The-Long-Kindle-Single-ebook/dp/B0060ANFPG/ref=pd_ts_zgc_kstore_5688113011_9?ie=UTF8&s=digital-text&pf_rd_p=1589452582&pf_rd_s=right-4&pf_rd_t=101&pf_rd_i=2486013011&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=0...
Also read Finding Ultra by Rich Roll and Born to Run by Chris McDougall. If it's important to you to run an Ironman, you will do it. Rich did five in six days...