For centuries there have been occasional accounts of free-floating spheres of light, sometimes destructive, that occur during thunderstorms. These are one of those mysterious phenomena people like to spend a lot of time speculating on.
I always figured they were something like afterimages of lightning flashes, narratively exaggerated in the confusion of dangerous storms.
But a story in New Scientist indicates that they may be actual brain effects, with strong fluctuating magnetic fields resulting in electric fields that cause neurons to fire through transcranial magnetic stimulation. A fast series of lighting return strokes can actually manipulate your brain into seeing something that's not there.
By this theory, ball lightning isn't real, but it's not made up either. It's a shared brain effect caused by magnetic fields. A camera would show nothing.
Charming, though I don't believe it. But it's interesting to think what other effects might result from shared manipulation of neurons, and what the cultural effects might be if it happened with fair frequency.