My take on it is that he chose a random number to illustrate what a flipping slog it's been in general, perhaps since waking up. How many times have you personally thought you had reached your wall, or at least got close to it?

Honestly, it's feeling quite like humans were made for this...to just keep going no matter what, even when we think we can't take another step. Maybe the words will mean something different to everyone who reads them, but they certainly are thought-provoking.