Good question.
I used the wrong word “memory” implying “nama gotta.” It is retained in “temporary bhavanga” or a “temporary state of mind.” I have added #5 there to address that issue as follows. Let me know if it needs further explanation:
5. In the last two Tadārammana (T) cittā, the mind takes in the “flavor” or the “essence” of the sense object and then falls back to the bhavanga state at the termination of the pancadvāra citta vithi. Only the very strong (mahantārammana) citta vithi have them, and such strong impressions are “retained in one’s memory” for a period of time (i.e., one will not forget immediately.)
Until one loses that “temporary memory” it becomes one’s “temporary bhavanga.” For example, when one hears about the death of a parent, one will become sad and that “sad state of mind” will be there for days.
That is explained in detail in the post, “State of Mind in the Absence of Citta Vithi – Bhavanga.”
Of course, ALL happenings are recorded as nāma gotta. Even unimportant events are recorded. The ability to recall events and what detail depends on one’s capabilities. Sometimes, such limited capabilities become possible due to “puñña iddhi” for even average humans. See, “Recent Evidence for Unbroken Memory Records (HSAM).”