You know how some people are instantly scared of snakes, spiders, heights, large cats? Those are some kind of genetic memory, passed down as a survival skill without having to be learned. These sorts of reactions are common to almost all mammals, and inherent to species survival.
I wonder if birds remember being dinosaurs? I see them strutting around parking lots as if they own the place. I can't help wondering if, somewhere in their little pea brains, they're thinking, "Just you wait, mister. All this used to be MINE, and someday will be again."