It’s essentially sentience vs sapience. The beavers are sentient because they can sense and perceive their environment. This information input then over time leads to the damn building behavior because it creates a selection pressure where beavers who build dams survive and reproduce more.

In a lot of ways you could look at our own sapience as the same as beaver dam building behavior. Pattern recognition likely allowed us to develop sapience by giving us the ability to make predictions about the future based of previous information. Overtime this could have allowed us to be able to create models of or environment that do not correspond with our current environment (imagination). At some point in the process sapience arose. This, for obvious reasons, turned out to be an extraordinarily advantages trait for almost any environment. So our ancestors with these traits survived more easily and passed those traits on.

As some people will likely attest, we sometimes blindly think about things for no reason. Thinking is our dam building behavior in a way.