Deja Vu

Maybe that's why we get deja Vu...you have a dream in your subconscious while you're sleeping, but since your brain experienced that for such a long time, your conscious self starts to pick similarities and scenarios out from your environment. And because most of the time it's identical, you feel that you've been through that before. But you don't remember it because you have a dream in your subconscious mind, not your conscious mind, and although they're technically connected to each other, your subconscious experiences have very little affect on your conscious memory. Maybe that's why you sometimes wake up and find out you woke up in the middle of the night and did something weird, but you don't remember it, because at the time, you're consciousness is stuck in some kind of limbo.

Frank: "hey Ricky?"
Ricky: "ya, Frank?"
Frank: "I feel like this happened already"
Ricky: "Deja Vu?"
Frank: "Deja Vu"