What do we really know?

What do we really know? Suppose our life was just a bunch of frames like in a movie. Now let's assume that the arrow of time is encoded in each frame. Now let's say we scrambled these frames so that they no longer are in what we perceive to be an order. At each frame all you know is what you've just done according to the arrow of time and where you are about to go according to the same arrow. If we were then to play that scrambled movie, would we experience life in the same way? How would you know you haven't just done to a future frame and back if the only thing you can perceive is your current frame and its past experiences. The only thing we actually know for a fact is that we exist in a place. We could be in a computer game from some other location and dimension but all we know is what we can do inside our mind.