this is a great way to look at it. honestly most people think it's about the vanity of being on stage, but like you said, it's really about that "no-negotiation" deadline. there is something about having a date on the calendar that makes you stop making excuses for that one missed meal or the extra 20 mins of sleep.
for me, the most surprising thing was the mental clarity that comes with the "deprivation" near the end. you realize how much of your day usually revolves around comfort and food, and when you strip that away, you find out what you're actually made of. prep definitely exposes those habits- good and bad! good luck with the rest of it, the discipline you're building now is gonna carry over into everything else in life man.