This makes no sense, you're either free to choose or your life is predestined. If your life is predestined then your choice is not yours to make since it already been programmed for you.
This seems more reasonable, in other words God has an idea but does not know.
I myself don't believe in any of this stuff but I had an interesting debate with two coworkers (One Christian and the other was Muslim), they believed that they had free will but that God knew the outcome of their choices, which makes no sense.
Is this how you define predestination? or you have a different definition for it?
the belief that everything that will happen has already been decided by God or fate and cannot be changed.
If this is how you define it also, then i think you are confused between God deciding something and knowing something in advance.