Reintegrating the dismal science
There are a number of ways to explain what money is, and what it allows us to do. Sadly, the "origin story" that we were all taught in school is a very misleading morality tale, in which exchange of goods is presented as a wholly separate sphere of life. Supposedly, humans were stuck with a so-called "barter economy" until they invented money. This is a complete fairy tale, and this matters a great deal.