On Memory (1)

Yesterday I heard a most beautiful and sad story. It is a story I've heard before and you might have as well. But this time it didn't strike me as horrific as the last time I came across it. It is the story of Clive Wearing who, after a viral infection, lost in the age of 50 all of his past memories as well as the ability to create new ones in what the neurologists call a combination of retrograde and anterograde amnesia. Clive has a new conscience every few minutes. No experience from the distant or recent past makes sense to him. He has no association between his self and this world apart from that minuscule time interval that his short term memory is able to maintain. So, he strives to define his existence anew every few minutes by keeping entries to a diary. But the entry is always the same and repeated again and again with only the slightest of alterations: 8:40 am "Now I am truly awake for the first time". 9:05am "NOW I am perfectly overwhelmingly awake". 9:17am "Now, yes now I am actually awake". An infinite loop of awakenings in this world. A cycle of rebirths, lives and deaths, each obsolete entry in his diary being an inscription on a graveyard devoted exclusively to him.
Yet Clive does remember one thing. He remembers his love for his wife. This is the memory he chose to hide in the deepest refuge of his cortex when the virus started sweeping across his brain. Every time he encounters her he greets her in the most passionate and joyous of ways. Even though he may have seen her only a few minutes earlier, he welcomes her every time with the sweetest words and kisses, like a lover reuniting with his partner after having being separated for years. Clive's memory of his wife has transcended his tragedy to become the most powerful incarnation of Paul's Hymn to Love.
Proust has this nice metaphor for memory. He says "[memory] Comes like a rope let down from heaven to draw me up out of the abyss of non-being". If you had just one memory to salvage, one memory to rescue you from your non-existence, a single engram tying your soul to this world what would that be?
Documentary on Clive Wearing