That someone is us.
We need to know how to build things, and how to fix things. We need to have ideas of how to get many things going again. And we need to know how to survive in somewhat primitive - or desperately primitive - circumstances. If you already can build a wood deck, for example, learn how to frame a house. If you can drill and tap screw holes in metal, learn to weld. Let's learn new things. In addition to how to fend off the Mutant Zombie Biker hordes.
I truly hope we don't have a total collapse of civilization. My hope is that the society remains, but like that quote from Ferfal in the second part says, society gets coarser, crime gets worse, electricity gets spottier, and life simply just gets harder in every way. Perhaps that's best case. I have to admit that years of working in an air conditioned environment has made me almost dependent on it. Even the hours I've spent out riding my bike or fishing or hiking (or whatever) hasn't prevented it. I really need a cool room to sleep comfortably. In the summer around here, temperatures can stay above 80 all night, or only dip below for a couple of hours before dawn (6AM). I expect some tough times if energy supplies get really spotty. I also expect that after a few days of not sleeping, I'll pretty much just pass out.
Tuesday's Business Insider has a column by Christopher Whalen of Institutional Risk Analytics saying "The Fed's Zero Rate Policy is Destroying America". He points out one of my (sounding like a broken record) points: the inflation they are pumping into the system is destroying "grandma". Not just those who are currently retired, but those who are trying.
If you are a saver, the Fed has crosshairs on you. Your savings are going to be destroyed. Again, they believe the way to save the government is to inflate the currency; you and I are just collateral damage. Don't worry, they'll throw you a bone. Or a strip of leather to chew on. Whalen also predicts the collapse of the Fed in that article, but from legislation not from economic effects. I have read the other way around, also. Remember, this is the "richest" organization in the world. In many ways the US government is a wholly-owned subsidiary of the Federal Reserve Bank. Do you think they go down without a fight? Do you think mere laws will do it? They have already ignored court rulings and other legal decisions. It seems to be one of those situations where no outcome is "good".