Here's an interesting concept though - and brace yourselves, this is a bit heavy, philosophical almost.
Have you ever wondered what exactly "time" is? Why is it that we can experience "now", but we can only remember the past, and we cannot remember the future?
Well it transpires that once you get your head around Special and General Relativity, there is no such thing as a universal "now" on which everyone can agree. It is a flawed concept. "Now" for someone on a distant planet is not the same "now" as for you or me, nor is the same for someone whizzing by on a fast moving spaceship. And since we all experience different nows, it follows that what's in the future for us, is in the present for some other beings. And what's in our past is in other beings's future. Bizarre, but true.
Our future very much does exist, it's simply that we cannot see it yet.
Imagine that all of our space at a moment in time is represented by a slice in a loaf of bread. One slice somewhere in the middle is our "now" slice and a slice to the left is "now" as it was a second ago. The whole loaf exists and the future slices are all there. They permanently occupy their particular point in spacetime. Aliens on another planet where gravity was much higher, or who were travelling much faster, would slice the loaf at a different angle. So their concept of now would be a different slice that would contain things that are in both our past and our present slices. To these aliens both our past and our present could be their "now".
So the future is mapped out already. But does this mean we have no freedom of choice, no free will? Well yes and no. No in the sense that no matter how much you try to outwit yourself - by pretending you are going to make one choice, and then at the last minute changing your mind - you were always going to take that choice, and the choice you make is inevitable. You just don't know it yet.