When Christianity was so new it was still just a guy named 'Christ' without the '-ianity', Genesis was already an ancient story that people had been interpreting and reinterpreting countless times over. Later, when the institution of the Catholic church grew out of the Roman state, it would be used as evidence of 'original sin' -- but I don't believe it was particularly central to anything Christ himself preached.

If you permit me a little reinterpretation of my own, of late I've been thinking about it more as an allegory for industrialization. In the same way people take 7 days and point out, "What is 7 days to God? Who's to say those 'days' don't encompass everything from the big bang to the evolution of mammals?", it's interesting to draw a parallel between 'garden' and 'ecology'. People found themselves in creation and although they didn't understand it, they lived with and within it. They were a part of it and it was a part of them.

Similar to elongating seven days, eating the fruit could be read as a very long process. An understanding of the physical world slowly being born out generation by generation. Being 'cast out' wouldn't be so much a curse, as the natural consequences that come with it. Now, we understand the garden, yet we live apart from it -- not as divine punishment, but simply because that's how we've used the knowledge gained.