No. It's not about being amnesia or any kind of stuffs related to human's brain from scientific perspectives. It's recalling memory from our life view.
Once in our lives, we need to recall some memories we have experienced. Good or bad ones. We need to recall the memories to find out how far we have been making progress today. No need to be dragged on contemplating both good or bad memory, but we need them to reflect, to compare us in the past and us nowadays.
Yesterday in the classroom I re-conveyed somebody's brilliant statement which said: Life is an X + X + X. Yesterday is an X. Today is an X. Tomorrow is an X.
Yesterday is eXperience. Today is eXperiment. Tomorrow is eXpectation. X + X + X means, use our experience in our experiment to achieve our expectation.
That's why we need to recall the memory. A lot of memory will boost a smile on your face. Many kinds of smile. Bitter sweet, until the real sweet one. But still smile, with a hidden story inside it.
And I have just recalled mine, and I smile happily, very happy :)