Once, long ago, I had a very succinct nightmare. My mother and a nun came to see me. The dream was short, only one scene, and the atmosphere in the dream was ominous.

I woke up and immediately translated my dream into British English. A Mummy and None had come to see me.

Mummy, UK child's word for mother, and of course the Egyptian mummies.

That was all. It became a nightmare only after I had woken up.