The use of metaphors presents, in my view, a very interesting ability of the human mind. It is to present something as something else, to find common characteristics in two differing objects or states, which means the mind has (consciously or unconsciously) broken them up into something deeper; points of thought, particles of a scheme.
Let me give an example of what I mean:
In the famous Homeric metaphor of the sea, likening it to wine ("the wine-dark sea")...