Walden

I expected a book about living in the woods and found a book about accounting. Thoreau counts everything: the cost of boards, nails, beans. The point is not frugality for its own sake, but seeing clearly what a thing costs in hours of a life.

"The cost of a thing is the amount of what I will call life which is required to be exchanged for it."

A question it left behind: which of the things I maintain are actually maintaining me?