My high school required us freshman year to map out what classes we were planning to take for all four years and review it with a faculty member. The plan was not set in stone, in fact mine changed all four years that I was there, but the idea was to have us look at the big picture so we didn't dig ourselves into a requirements hole we couldn't get out of. My senior year I ended up adding an independent study that I can no longer recall when I decided on, I took a physics class that I'm guessing had not been my original pick for my last science credit, and I took pre-calculus, which had originally been on the plan for junior year, even though I had already satisfied my math requirement.
The excercise was worthwhile. And it reminded me that plans are, as they say, dreams written down, but the guide posts are still useful even if they change or get left behind when you move to a new path.