But in terms of how our brain works, and why it evolved, it really is prediction.

Prediction allows us to behave according to what is about to happen (or what we want to happen) as opposed to just reacting to what is happening right now. "I predict the sabre-tooth is going to run towards me, so I better be prepared", is more adaptive than "Ouch! this fucker has big teeth!".

When we're driving (well) we're continually predicting what other drivers/pedestrians are going to do, what's the best lane to be in for next exit, etc, etc.