Well, let me run down my early-game survival needs. Assuming I don’t have a container to store water, I’ll need a waterskin. To make that I need a sewing needle. To make a sewing needle, I need a knife to carve wood or bone. Also need a knife to make the skewers for a fire drill, assuming I lack a lighter. And the skewers are nifty for early-game cooking.
So in theory, a knife would be my single most important survival item, just like in real life. But wait, hold that thought a moment. Unlike in real life, makeshift knives can do all this cutting just as well as a proper knife, and they’re trivial to make? And just what is the first step to making the basic makeshift knives, which ALSO happens to be essential for making a stone pot for boiling water?
A rock. Or really, anything with a hammering quality of 1. But still, if you’re starting from scratch, Mr. Rock is your friend.