When I’m tired, I hallucinate. As a consequence, I am wary of my own visual perceptions sometimes. So, there I was, shattered and not of good head, standing where a stream comes down to meet a path. I could see movement in the stream, and as I watched it looked increasingly like a little bundle of leaves was making a conscious descent down the tiny waterfalls. “Ah,” says I to myself. “Hallucinating, then.”
As it was weird and wonderful, I kept watching, as the leaves worked their way down. When they landed in the lowest pool, they stayed together, and I could see them that bit better. Not leaves, but legs, pincers… something weirdly like a lobster. A small light came on inside my head and I realised I was looking at an American crayfish. I’d never seen one before, but know they are around as an invasive species.
It’s very hard to make sense of things we don’t know about. We tie our observations to the familiar. My son, aged about three, finding a lizard in the garden and knowing nothing about lizards, was convinced he’d found a dragon. I recall a tale of confused people finding a monkey and thinking it was a Frenchman. We aren’t good at processing what’s alien to us. We are predisposed to thinking we’ve seen something familiar. The implications of not seeing what we don’t know about are vast. I saw leaves. It took a real effort to realise I wasn’t seeing leaves.