Particularly dangerous are old men who retain the memory of past events, but do not remember how often they have repeated them. I have known some very amusing tales to become most tiresome when told by some gentlemen whose whole audience has been sated with them a hundred times.

[Sur tout les vieillards sont dangereux, à qui la souvenance des choses passees demeure, et ont perdu la souvenance de leurs redites. J’ay veu des recits bien plaisants, devenir tres-ennuyeux, en la bouche d’un Seigneur, chascun de l’assistance en ayant esté abbreuvé cent fois.]

Michel de Montaigne (1533–1592) French essayist

Essays, Book 1, ch. 9 (1.9), “Of Liars [Des Menteurs]” (1572) [tr. Cohen (1958)]
    (Source)

This essay was included in the 1st (1580) edition, and expanded in 1588 and 1595. This particular passage was added for the 1595 edition. See also La Rochefoucauld (1671).

(Source (French)). Alternate translations:

Above all, old men are dangerous, who have onelie the memorie of things past left them, and have lost the remembrance of their repetitions. I have heard some very pleasant reports become most irkesome and tedious in the mouth of a certaine Lord, forsomuch as all the by-standers had manie times beene cloyed with them.
[tr. Florio (1603)]

But above all, old Men, who yet retain the Memory of things past, and forget how often they have told them, are most dangerous Company for this fault; and I have known Stories from the Mouth of a Man of very great Quality, otherwise very pleasant in themselves, become very troublesome, by being a hundred times repeated over and over again.
[tr. Cotton (1686)]

But, above all, old men who retain the memory of things past, and forget how often they have told them, are dangerous company; and I have known stories from the mouth of a man of very great quality, otherwise very pleasant in themselves, become very wearisome by being repeated a hundred times over and over again to the same people.
[tr. Cotton/Hazlitt (1877)]

Above all, old men are in danger, who retain remembrance of past things and have lost remembrance of their twice-told stories I have known some really amusing tales to become very tiresome in the mouth of a man of the world, every one present having heard them poured out a hundred times.
[tr. Ives (1925)]

Old men especially are dangerous, whose memory of things past remains, but who have lost the memory of their repetitions. I have seen some very amusing stories become very boring in the mouth of one nobleman, everyone present having been sated with them a hundred times.
[tr. Frame (1943)]

Old men are particularly vulnerable: they remember the past but forget that they have just told you! I have known several amusing tales become boring in one gentleman’s mouth: his own people have had their fill of it a hundred times already.
[tr. Screech (1987)]

The most dangerous are the elderly who have kept their recollections of the past but have lost track of their sharing them. I know of pleasant tales told by a certain gentleman that turned quite boring after each member of his audience had been regaled with it a hundred times.
[tr. HyperEssays (2025)]