Inside jokes are the only currency that goes up in value the longer you hold it.

Shared history compounds. A joke that made no sense to anyone outside the room gets funnier every year, not because the joke improves but because the years of being known by the same people stack up behind it. Three words can carry a decade. That is not really about humour, it is about having witnesses to your life.

Use one this week on purpose with someone you have drifted from. It is a low-cost way of saying you still remember, and it restarts a conversation faster than asking how they are. Then go and make some new ones, which mostly requires spending unremarkable time with the same people repeatedly.