When I first saw Henri Cartier-Bresson's photographs, in his own words "I suddenly understood that a photograph could fix eternity in an instant."
And again in his words;
"There is a creative fraction of a second when you are taking a picture. Your eye must see a composition or an expression that life itself offers you, and you must know with intuition when to click the camera. That is the moment the photographer is creative"
I pretty much think of it the same way regardless of what I may photograph, whether it takes hours or seconds to set up the shot, it's all for the decisive moment when it just clicks (Probably the reason I don't like those strange digital cameras that don't have a shutter but make a sort of whooshing sound from a small speaker)