Or are we dreaming what is already pre determined?

To specify, I can't really specify. It will always happen while doing completely unrelated tasks.

For instance, I was flipping through my textbook last night reading and suddenly I thought I was experiencing deja vous. But it wasn't!!! There was no way I read this before!!! I am not one to read ahead and when this page hit me I knew it. I got a dread feeling all over and I recognized the first sentence I read as if I had read it before.

This isn't the only occurrence, however they all seem to reveal absolutely nothing relevant....