I've come across this before, especially from folks who are from suburban and city areas, (i.e. inside the M25 Ring road in the South of England it never really gets truly dark) when taking them into areas where there is no urban light pollution. Some folks have never seen or experienced true darkness being brought up all there lives in the city and suburban areas.

They tend to panic when this happens, when the bright fiery ball in the sky lowers beyond the horizon.