The Private Papers of Henry Ryecroft by George Gissing

Everyone, I suppose, is subject to a trick of mind which often puzzles me. I am reading or thinking, and at a moment, without any association or suggestion that I can discover, there rises before me the vision of a place I know. Impossible to explain why that particular spot should show itself to my mind's eye; the cerebral impulse is so subtle that no search may trace its origin. If I am reading, doubtless a thought, a phrase, possibly a mere word, on the page before me serves to awaken memory. If I am otherwise occupied, it must be an object seen, an odour, a touch; perhaps even a posture of the body suffices to recall something in the past. Sometimes the vision passes, and there an end; sometimes, however, it has successors, the memory working quite independently of my will, and no link appearing between one scene and the next.

Ten minutes ago I was talking with my gardener. Our topic was the nature of the soil, whether or not it would suit a certain kind of vegetable. Of a sudden I found myself gazing at -- the Bay of Avlona. Quite certainly my thoughts had not strayed in that direction. The picture that came before me caused me a shock of surprise, and I am still vainly trying to discover how I came to behold it.