I have not read Marcel Proust's huge, lumbering Remembrance of Things Past. But I have read the first volume, Swann's Way, twice, at two different times in my life when I set as my summer project doing the "big read." Doesn't every dedicated reader set out at some time in her life to read Proust? Does anyone actually finish?
It has long been thought that the role of memory is not just to remember the past, but to enable us to predict the future. Proust's prodigious memory conferred little in the way of survival value, except insofar as it enabled him to more advantageously negotiate the future. The person who remembers the crocodile in the river will dive in with care. Many biologists believe that the ability to imagine possible futures was the central driving force in the evolution of memory. Some recent studies of patients with amnesia caused by damage to the hippocampus, the brain region intimately associated with memory, show that their ability to imagine the future is also impaired -- a conclusion that seems to me rather self-evident.
Great works of literature -- Tolstoy, Joyce, Proust -- would also seem to be enabled by particularly sensitive and capacious memories. War and Peace, Ulysses, and Remembrance of Things Past may be felicitous by-products of natural selection.