OK, so the next riddle is "What is free will?". Following on the previous "book" analogy, I like to use the video game analogy especially a video game on a CD (remember when?!). The video game exists in its entirety now but has to be played in sequence (that's the past present and future all exist now part, like in "the book"). You absolutely have free will about how you play the game but all of the end results are pre-determined by The Programmer (a.k.a. God, Fate, The Universe, ... fill in the blanks).