Well, yes of course we can. PBP attracts a lot of riders. I've ridden with a few finishers. They're not abnormal, they just know how to keep going, which of course means keep eating. I've only done 400k rides, but 18 hours ET is a long time. I'd usually be stronger at the end than at the beginning, as then I'd know when the end was. I'd eat mostly carbs, a little protein, very little fat. I'd have a couple slices of pizza at the end, drive home and go to bed.

Way early in my bike life, like when I was maybe 53 and rode my first 50 mile ride. After about 30 miles, I started to feel dizzy, got off the bike and sat in the ditch while the world went around. I ate a bagel, drank some water, and 10 minutes later was on my way again. Never did that again. One has to keep up a steady intake. I start eating after the first 15' and then eat every 15', establishing a pattern. No need to wait until one is sitting in a ditch.

That said, as the years went by, I became more resilient but on serious really long rides would still eat every 15'.