Memories are made of this

We take memory for granted, never missing the water until the well runs dry. It carries us on a continuous, conscious journey providing holiday snaps. There may be gaps, the vision may be darker, fainter, further away, faulty. It may be fast failing but, unless we are unfortunate, it never seems to fail catastrophically and permanently. What if it did?
We refuse to believe it could. There would always be a part of us that knew we preferred red to white wine, did not take sugar in our tea and hated country music! Would we?

The novel, Before I Go To Sleep, by S J Watson explores this.

It takes an extreme form of amnesia, the inability to retain memories from day to day, and makes it the central plank of a thriller, a real cracker. It explores our ideas of permanence of memory and identity and how they could be undermined fatally. If they were, what would that mean for our independence and sanity? The situation of the amnesiac in the novel creates the psychological equivalent of the murder in a locked room. How can I trust other people, their versions of reality and even myself if I cannot bring my own tenuous recollections of yesterday and before to bear on them?

Now where did I put my glasses?