The Depth of Memory Is Determined by the Manas

Question: Why can a person with senile dementia fail to remember the people most familiar to them?

Answer: Familiar people are not necessarily the people they are most interested in or the people most important to them, which is why a person suffering from senile dementia may fail to recall or remember them.

After a problem arises in the brain's supreme faculty (indriya), an elderly person's memory of past events from long ago remains quite clear, and they always like to recall the people and affairs of their childhood and earlier years. But they have little impression of people and events from recent years; they have memory of and interest in the people they care about and like most, while having little impression of others. Because as age increases, the brain's supreme faculty (indriya) undergoes more and more degeneration, causing the memory function to become worse and worse, 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, and as long as the sixth and seventh consciousnesses are free of disease, they can be recalled. Memories of one's later years are poor, so those things will not come to mind.

Some deeply unforgettable matters, as one approaches old age, remain ever fresh in memory—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 much it wants to. A person with senile dementia does not recognize you and cannot remember you, which shows that you are not important to him. The person he constantly keeps in mind, in speech and in heart, is the person most important to him, the person he is most interested in. Moreover, a person with senile dementia has selective memory and selective amnesia, which is related to karmic affinity and to the state of the brain at the time. Whether a person has you in his mind consciousness and on his lips, or has you in the heart of his manas—by now, having studied up to this point, it is not difficult for us to judge.