An old sibling joke can remain affectionate after its original truth has disappeared.

Jokes outlive their facts. Somebody was hopeless at directions at nineteen and is now the person everyone relies on, and the joke continues, stripped of accuracy and carrying only the affection. That is mostly harmless and occasionally not, when the person hears an old verdict rather than a warm one. The same words do very different work depending on whether growth has been noticed elsewhere.

Keep the old jokes, and make sure the current version of the person gets acknowledged out loud too. If one of them ever seems to land flat, it is worth asking rather than repeating it more cheerfully.