Are shadows always there and is darkness a shadow?

Okay, before we get too metaphysical or occult- a Shadow can ONLY exist if therfe is some available light, sun or moon, artificial light, etc. In absolute darkness a shadow cannot exist! I used this angle to disprove an old family story about a woman who was walking home one night near the Armory ( In Jersey City) and seemed to have an encounter with a moving shadow of the Stuyvesant statue! First of all the Sturyvesant statue, peg leg and all, is not that near the Armory, second , if it was a really dark night, as it was in the story, a shadow would not show. For the same reason Sun dials ( which indicate by a shadow) do not work in overcast days- bad weather or cloudy like now as I am typing this- and of course not at night but could reflect moonlight. No light, no shadow. so it goes.