I have said elsewhere that memory cannot exist without attention, and that where there was no attention at all paid to something, it is impossible for any recollection of it to remain or come back. Attention can be greater or lesser and according to the memory (natural or acquired) of the person, and according to the greater or lesser durability and keenness of the recollection which follows from it. It can indeed be minimal, but if any recollection at all is present, it is certain that some degree of attention preceded it, It can also be the case that someone is not aware, does not think, does not remember that he ever paid any attention at all to that thing that he remembers, but in such as case, which is not uncommon, he is deceiving himself. Perhaps the attention was involuntary, perhaps it was even against his will, but it was no less attention for all that. If the particular thing struck him, made him pause, even only momentarily, even only very slightly, even decidedly against his will, even if he immediately turned his mind away from it, that is enough, the attention was there; that it struck him is the same as making him pay attention, however little and for however short a time, but making him do it in spite of himself. (Z3737) Leopardi – Zibaldone
