First, in this case, both you and I would agree that the ground is wet. So would anybody who experienced it (excepting loonys). That constitutes evidence. The conclusion one could draw from that evidence is wide open - as you say, many conclusions are possible depending on your background and experience in evaluating wet ground. Some of those explanations we would find improbable, ludicrous, or (as medved would say) stupid - doesn't matter, we all agree on the evidence.
You see "evidence" of a god when I scratch my ass. I don't. Most people wouldn't. Other theists would differ as to which god is evident in my scratching of my ass. The conclusion you draw is totally irrelevant if we can't agree on what constitutes evidence in the first place.
Also, if the sum total of your "evidence" is the existence of our universe or "we" as a species, you can all quit wasting our time in this discussion. We see the existence of our universe, and ourselves, as evidence of *Univ, a continuous creation-destruction cycle of universes, an eternal universe, a creation-by-a-giant-chicken-named-Harry-from-Pasedena-universe, or whatever-floats-your-boat-explanation. It's simply not relevant to the discussion because all "creation theories/creation myths" are equally unverifiable and equally inconsequential in their ramifications.
Finally, given the number of views of the creation question in science, literature, philosophy, and mythology around the world, and the spectrum of primitive creation myths around the world, why is yours any better an explanation than any one of them selected at ramdom?