Money is energy, so money is good.

A note left in a drawer for two years does nothing whatsoever.

The same note buys a birthday cake on Saturday and has suddenly done a great deal — become an afternoon, a room full of people, a thing a child still remembers at forty.

None of which is an argument about saving. A buffer is doing plenty simply by sitting there, absorbing a month nobody could have predicted.

But money mostly shows what it is at the moment it moves. It becomes a train ticket, a plumber, a taxi at midnight for someone who should not be walking home. Held still, it is a figure. In motion, it turns into the actual furniture of a life.