remember you don't have any access to objective reality. everything you see is your brain's reconstruction of nerve signals coming from light hitting your retinas. optical illusions happen because sometimes your brain misinterprets the inputs, which highlights the fact that what you're seeing isn't "real" but a representation of reality that isn't always accurate.

your memories are stored in your brain, they're also not real and they don't necessarily correspond to reality. you can make time slow down through certain methods that cause data to load into your short term memory incorrectly. time isn't really slowing down, but your brain's stretching out the experience in your memory and since you live in brain-world, not real-world, you experience the stretched reality.

so if your brain accidentally sticks something in your short term memory before it consciously registers the thing, once it registers the thing it looks back and says "oh that already happened." it has no way of accessing the real world to correct itself, it can only trust its own reconstructions.