If you really wanna stop sleeping at night, get this: the human brain's memory system doesn't work like we think. There is no recorded data like on a hard drive, every time you remember something you are basically running a simulation in your head of those experiences, and the conditions are managed as associations only. This is why memory is so unreliable.

I will leave it to you to toss and turn and work out what this means for your experience of the universe.