We are. At least that's what Lisa Feldman Barrett [1] thinks. It is worth listening to this Lex Fridman podcast: Counterintuitive Ideas About How the Brain Works [2], where she explains among other ideas how constant prediction is the most efficient way of running a brain as opposed to reaction. I never get tired of listening to her, she's such a great science communicator.
Interesting talk about the brain, but the stuff she says about free will is not a very good argument. Basically it is sort of the argument that the ancient greeks made which brings the discussion into a point where you can take both directions.
[1] https://en.wikipedia.org/wiki/Lisa_Feldman_Barrett
[2] https://www.youtube.com/watch?v=NbdRIVCBqNI&t=1443s