I used to know. I used to believe 100% in the Lambs Book of Life. I used to believe that God knows everything I'm going to do. But I got older. The age of reason, mind you. Now I do believe in God. I mean sometimes just explaining things away as a higher power did it just makes me feel better. But I'm also a person of reason, and if I can reasonably figure something out then I don't need to fall back on the time-tested "God did it."
I believe God isn't your over protective grandfather. I do believe in Free Will over predestination because that makes more sense in God's character. He created us, then let us loose. He would rather us live good lives, but it's up to us whether we will. Now I think God is a smart enough guy to know where we might be going, but I don't think he's already penned me in or out of the Lambs Book. If that were the case then why would there be a final judgement? No. God wants us to be good people. But we have the right not to be.
I think the big mistake about God is people expect Him to be a hands-on control freak. If that were the case we wouldn't have Wars. If God loves everyone, then why would he send them to Hell? Free will. He doesn't want mindless drones to spend eternity with, he wants individuals.
But that's my opinion.