The loss which is unknown is no loss at all.

A thing you never learned you had lost costs you nothing in the only place cost is felt, which is your attention. Much of what we call misfortune is really the discovery of misfortune, and the suffering starts at the discovery. That is not an argument for ignorance, only a description of where the pain actually lives.

The practical use runs in the other direction. When you are deciding whether to tell somebody something, ask whether knowing it will let them do anything. And with your own losses, notice how much of the weight is the fact of it and how much is the going over it.