The brain I use to conjure up those ideas is, from a purely physiological view, the same that Mr. Caveman used to dream up his world view. Hence I do actually consider myself able to come to the same kind of conclusion if presented the same facts.
Totemism and animism are two of the ways humans fill in the gaps in their understanding of the world. That's what we always did since the dawn of our self awareness, I'm convinced. We were asking questions about us, about our place in the universe and the universe itself. We observed. We pondered. And just as we do today when we put up the hypothesis about dark matter and dark energy because there are obviously things happening in the universe that go beyond our understanding and what we consider "real" and "right", so did human back in those days. Of course from a completely different vantage point.
Just as it makes a lot of sense to us now that there must be something that we cannot detect other than with its gravitational pull, it made a lot of sense to the early human that there are certain supernatural entities that he cannot detect other than by their effects, by the change of the seasons and the way his world affected him. It made sense to him that there was some kind of spirit, god or other otherworldly existence that sent him dreams and caused good and ill. And he tried to understand the motivation behind it, he tried to understand his "god", and even to a certain extend, to control what happens. To appease the gods, spirits or other entities.
If you ask me, that makes a lot of sense.