I remember the good old days where you didn't get to see the schedule until you showed up for the convention. Would get together with the gang with a yellow highlighter and mark off all the panels we wanted to see. We never get to them all. Sometimes we would wander around and find something unexpected to do - that's part of the fun is just wandering into a panel you'd normally never sit in on and actually have a great time learning something new.
Funny side story, I used work in the same building as the guys who use to print the schedules (Sir Speedy on Alameda, dunno if they still get them printed there). Never did try to get a sneak peak, though it was tempting =)