A few bits of personal observations:
Food becomes an inadvertent countdown calendar on these hunts. Each day finds me counting what's left and adjusting my eating to balance things.
If you don't have it, make it. If you can't make it, learn to live without it. If you can't live without it, you might as well give up.
Expiration dates mean nothing. Food labels, batteries....you won't throw something away because of a date. Everything is important.
A stack of firewood is more valuable than a stack of money.
Credit cards can be used for reading material when you're bored.
A big handgun is an adult teddy bear at 9 pm.