This is how dumb a bear is: He has already ascertained that the top of a pole is a good place to be (don't worry about how he came to that decision, that's a different discussion), so when he was forced down from that pole, he doesn't process the new information that the top of a pole invites humans, and attempted lynching, he immediately defaults to his previous decision to run up the next pole!

But then he finally demonstrates what has brought him 3/4 of the way up the food chain: he stops halfway up the pole, and reflects on a new concept. As he looks into the distance, about to shimmy up that pole, he sees emptiness, no humans with poles and nooses at all. That just might be a better idea than climbing this pole.

It takes him a while to process this new concept, but he eventually makes his best Darwinian decision, and runs for it!