I came across this quote when researching David Carroll, author of the middle grade debut, Ultra:
you’re suffering from hypothermia, or excruciating chafing, by all means, take
some time off to recover. Otherwise,
keep writing. The finish line is out
there – somewhere."
David Carroll, author of Ultra, To DNF or Not to DNF, December 13, 2013
Even though I don't do marathon running (or any kind of running, for that matter), I can totally relate to the drive to push past obstacles to reach a finish line, whether it's the end of a chapter or the end of a novel.
Sometimes in the middle of a novel it can feel like you're lost or trapped and can't see the way out. But if you keep going, you'll eventually get to the end. You just have to keep going!