We were already working on something for them, and on a whim, one of their VPs asked my company if we could take a look at it.
So that's how the mathematician at the company (me) ended up waking up, sitting in front of a whiteboard, and losing all concept of time until my wife got home from work at night, not eating, not sleeping, staring at decompiled assembly and stepping through line by line for weeks. (I don't want to say months because I'm sure someone will come roast my ass for taking too long, but "months" is honestly more accurate; in fairness, I was learning every technique used on the fly)
It was a prolonged, repeated flow state that I've only ever experienced during really competitive tennis as a high schooler. Losing all concept of time and space, hyper focused on one task that has completely spread to all parts of your consciousness.
Turns out, in the real world, people like having nice things, hanging out with family and friends, travel occasionally, etc. instead of just entering flow state to solve problems! It has nothing to do with income inequality.
Good luck, your project is very impressive and I hope you are able to continue to make cool stuff!
1. I've also been it a hyper-focused state where I was so intent on what I was working on I would spend basically all my time on that project without burning out. Like you, I haven't hit that focus state for a long time.
2. "18+ hour days", consecutively, is almost certainly an exaggeration, and this is where I agree with the parent commenter. For some reasons Americans (I am American) love talking about how much time they work and how little sleep they get. Realistically, very few people (except a small percentage of genetic outliers) can get by on sub-6 hours of sleep for long.
I don't know, when I got hyperfocused on a side-project a few years ago, I was dedicating almost all my awake time to it. 12+ hours a day, every day, including weekends, for months.
Surprisingly, I didn't burn out. I was just so interested in it, I couldn't stop, and even started neglecting other things to work more on it.
I never hit such a focus state since that time in 2017~2018.