Amy Tan "Confessions"

"Confessions" brings up many interesting questions of memory reliability and perception. Tan gives us a memory of her Mother threatening her physically after her Dad dies. At the end of the essay, Tan confronts her Mother and her mother says that she had never been angry or hit Tan. For some reason The reader is inclined to believe this line from the mother even though it's second hand. Perhaps because it's second hand. Why does this memory exist if the event happened? And why is the word of the mother taken so easily? We learn that the Mother has alzheimer's but we still accept that line as true. maybe because Tan put it in the essay. partly because I don't want to believe that something so dark could happen and partly because memories get warped over time, I want to believe the last line of the essay, but maybe I shouldn't.