Charles Dickens on Visions

I have always noticed a prevalent want of courage, even among persons of superior intelligence and culture, as to imparting their own psychological experiences when those have been of a strange sort. Almost all men are afraid that what they could relate in such wise would find no parallel or response in a listener's internal life, and might be suspected or laughed at. A truthful traveller who should have seen some extraordinary creature in the likeness of a sea-serpent, would have no fear of mentioning it; but the same traveller having had some singular presentiment, impulse, vagary of thought, vision (so-called), dream, or other remarkable mental impression, would hesitate considerably before he would own to it. To his reticence I attribute much of the obscurity in which such subjects are involved.

The problem with visions only experienced by a single person.