You may well be right about most people, but in my experience it's not that hard. My wife and I have been fasting for 3 consecutive days each week for over a year (we worked up to it over the previous year). It's become pretty easy now. I rarely feel hunger.

BTW, I feel I must add (for the benefit of random readers stumbling upon this thread) that most people should not attempt long-duration fasting. It may not be beneficial at all, and there are certain dangers associated with it. Up to 3 days is probably okay if you're overall healthy, but most people should stop around this point (I can't draw a firm line as it's not an exact science). 1 week becomes pretty sketchy for everyone.

The human body could go on like that for a few weeks actually, but I don't think there are any benefits beyond 2...3...4 days [research needed], and the dangers multiply rapidly the more you push into very long durations.

Drink water with electrolytes during fasting, e.g. a little bit of salt. If you drink just normal water, it's hypotonic and you'll lose electrolytes, bringing you to a hangover-like state - that might be brutal then.

Depends on what you do while fasting. I couldn't fast one day under heavy mental activity. I feel nauseous when I'm deeply thinking while coding for too long without eating.