All writing has to be ’what you know’; it can reasonably be argued that you can’t write what you don’t know.【T1】Whatever we invent is based on something known to us—our own experience, to which we apply our imagination. And in those cases where we have to increase the stock of what we know—through research—our writing reflects our newly acquired knowledge.

We are already applying imagination to memory when we recall an event from the past.【T2】If you were to set yourself the ten-minute task of writing down a memory from your childhood and were then asked whether, in order to fill in any gaps in your memory, you had made anything up, you would be very likely to say that you had. In fact, you had been obliged to, because otherwise the narrative would have had distracting gaps or uncertainties in it. However, you would probably maintain that the account was essentially true.

The truth of an event may not, in any case, be easy to establish. You will probably recognise this experience: you are among old friends or family members when one of them starts to recall an event at which others were present.【T3】Members of the group will disagree on the detail—perhaps even on bigger issues—because the fact is that each individual has their own version of what happened. This is partly because they were experiencing it from their own unique perspective and partly because memory doesn’t unfold as a continuous spool of events and experiences.【T4】We don’t preserve a frame-by-frame record of the past; what we retain is more like snaps in an album, and we have not all taken the same snaps; we have remembered what seemed to affect us as individuals most deeply at the time. We can’t recall every incident which happened between the snaps, so we imaginatively reconstruct what must have happened between them. It is natural for humans to make connections in this way, to create narratives that suggest causes and effects.【T5】This is why dreams are at once so fascinating and so frustrating—they seem to be no respecters of cause and effect or of flawless narrative: we can step out of a restaurant and be on a ship, or get out of a corridor and be in a forest. It’s not a frame-by-frame narrative; connections seem to be missing. And our desire for connections—our desire to make sense—drives our automatic habit of filling in the gaps. When we remember, we are to a large extent reconstructing the past.

【T1】