You can look at it like this: we spend our lives doing just two things, evolving relationships and shifting atoms.
Any activity in one area affects possibilities in the other.
Every made object you see around you represents some exchange of effort between people, and therefore has as its origin a human relationship.
You may have never met the producers of most of the things you own; but still, each thing is the byproduct of a chain of relationships connecting those people to you.
A middle-class American family sits relatively near the top of a vast food-chain of relationships, of which all their physical possessions are the byproducts.
That which we call “Thrift” is simply maximizing the value that flows up to you through this chain of relationships, while limiting your own contribution up the chain.