Is Genesis 3 just a fable?

Alisa Childers correctly points out how disastrous it would be to Christianity, if Genesis 3 was mere fable.

So let's start with the obvious:

When I was a kid, and read about ancient tales in other cultures that made reference to talking animals, I automatically assumed that because we never see animals talking that this today, these tales are surely mere fictions.

Was I unreasonable to draw such a conclusion upon such basis?