The pleasures of memory must certainly be estimated high, but I am sure forgetfulness also plays a part in making human beings happy.
Some of the unhappiest people in the world are those who cannot forget injuries inflicted on them in the past. Others are equally miserable because they cannot forget wrongs they have done others.
Human beings are so contituted, indeed, that they forget the things they would like to remember, and remember the things they would prefer to forget.
The memory should be trained, I think, to overcome both these weaknesses.