Why is our memory good enough to recall to the last detail things that have happened to us, yet not good enough to recall how often we have told them to the same person?

[Pourquoi faut-il que nous ayons assez de mémoire pour retenir jusqu’aux moindres particularités de ce qui nous est arrivé, et que nous n’en ayons pas assez pour nous souvenir combien de fois nous les avons contées à une même personne?]

François VI, duc de La Rochefoucauld (1613–1680) French epigrammatist, memoirist, noble
Réflexions ou sentences et maximes morales [Reflections; or Sentences and Moral Maxims], ¶313 (1665-1678) [tr. Kronenberger (1959)]
    (Source)

See Montaigne (1572).

This first appeared in the 3rd (1671) edition. In the manuscript it read:

Pourquoi faut-il que nous ayons toujours assez de mémoire pour retenir tout ce qui nous est arrivé, et que nous n’en ayons jamais assez pour savoir combien de fois nous l’avons conté à une même personne?

(Source (French)). Other translations:

What an odd thing it is, that our Memories should serve us to recollect all the little Circumstances that have happened to us; and yet that we should not remember, how often we have told them over and over again, to one and the same Person?
[tr. Stanhope (1694), ¶313]

Why have we memory sufficient to retain the minutest circumstances that have happened to us; and yet not enough to remember how often we have related them to the same person?
[pub. Donaldson (1783), ¶301; ed. Lepoittevin-Lacroix (1797), ¶288; ed. Carvill (1835), ¶264]

Why must we have memory enough to retain even the minutest details of what has happened to us, and not enough to remember how many times we have told them to the same person?
[ed. Gowens (1851), ¶323]

How is it that our memory is good enough to retain the least triviality that happens to us, and yet not good enough to recollect how often we have told it to the same person?
[tr. Bund/Friswell (1871), ¶313]

Why is it that our memory recalls even the minutest details of our experiences, but cannot recall how many times we have told the same story to the same person?
[tr. Heard (1917), ¶320]

Why is it that our memory enables us to recall our own experiences down to the minutest detail, whereas we cannot remember how often we have recounted them to a particular person?
[tr. Stevens (1939), ¶313]

Why is it that our memory, capable of retaining the minutest details of what has befallen us, yet fails to remind us how often we have already recounted them to the same person?
[tr. FitzGibbon (1957), ¶313]

How comes it that our memories are good enough to retain even the minutest details of what has befallen us, but not to recollect how many times we have recounted them to the same person?
[tr. Tancock (1959), ¶313]

How is it that our memory is good enough to retain the minutest details of our lives — but not good enough to remember how very many times we have recounted those details to the same person?
[tr. Whichello (2016) ¶313]

Why is it that we have enough memory to recall the most trivial occurrences that have happened to us, but not enough memory to remind us how often we have told them to the same person?
[tr. Chandler]