The cancellation that disappoints one person can quietly make another person’s plan possible.

Every arrangement uses up something scarce: a room, a slot, an evening, a place in a queue. When it falls through, that scarce thing goes back into the world and lands, usually invisibly, with somebody who needed it. Your disappointment is real and it is not the whole event. Almost nothing that happens has only one set of consequences.

If you have to cancel something, do it early enough for the space to be usable by somebody else. When you are the one let down, allow the disappointment without adding a story about waste.