The Depth of Memory Is Determined by the Manas

Answer: A familiar person is not necessarily the person they are most interested in or the most important person to them, so a person suffering from senile dementia may fail to recall or remember them.

After a problem arises in the brain's supreme faculty (rūpa-prasāda), an elderly person's memory of past events remains quite clear; they always like to recall the people and events of their childhood and earlier years. But they have little impression of people and events from recent years, and they retain memory of and interest in the people they care about and like most, while having little impression of others. As age increases, the brain's supreme faculty undergoes more and more degeneration, causing the memory function to deteriorate progressively, so that many people and things can no longer be remembered. But the events of one's youth and childhood have already been stored in the tathāgatagarbha; as long as the sixth and seventh consciousnesses are free of disease, they can be recalled. Memories of one's later years are poor, and thus will not come to mind.

Some deeply engraved, unforgettable matters become ever more vivid in memory as one approaches old age—impossible to forget even if one wants to. The depth of memory is entirely determined by the manas. What the manas is not interested in, the mind consciousness cannot remember no matter how it tries. A person with senile dementia does not recognize you and cannot remember you, which shows that you are not important to them. The person they constantly keep in mind, in speech and in heart, is the most important person to them, the person they are most interested in. Moreover, a person with senile dementia has selective memory and selective forgetting, which is related to karmic affinity and to the state of the brain at the time. Whether a person has you in their mind consciousness and on their lips, or has you in the heart of their manas—by now, having studied up to this point, it is not difficult for us to judge.