I agree with Mike above that reading up on Freud may help a lot. Basically language is fluid and fundamentally open to interpretation. Unlike those who may believe language is a rigid structure wherein words, phrases, clauses have some 'essential' or unquestionable meaning, it's very much a culturally informed phenomenon. Meaning is inscribed through a mutual shaping; the backbone of a language (grammar, lexis) combines with cultures, societies, religion, along with personal experience and the subconscious. One of the easiest examples of this can be highlighted in the differences between the sense of humour of various countries. Look at sarcasm, or self-deprecative humour. Some people get it and some people don't (that's not to say you can make blanket statements about 'people from x country' get this etcetc, although there may be a tendency in Britain for example, for people to understand and find self-deprecative humour funny). A shorter answer would be that the snake is an 'allegory' for something else. Allegories occur very often in old prose, in fictional novels and literature (especially the classics). You also have metaphors, which occur in most poetry. You're an educated chap so I'm sure you'll get it in no time. Then again, maybe I'm wrong, and I've simply spent too much time hanging around with creative writers.

I'm in the same boat with you. I don't see the correlation either from my cultural context (western USA). I've noticed, at least in this country, that sometimes graduates with degrees in subjects of questionable value, such as creative writing or art appreciation, go too far in reading siginificance into things that really isn't there so that they can show themselves and others that the four years they spent getting their degree really was time well spent. They can end up over-analyzing things.

Post Freudian, not Post Fordian. Read some things concerning the teachings of Sigmund Freud and you will soon have your answer... http://en.wikipedia.org/wiki/Freudian