Early Rigistration Swindle

Yesterday I registered for classes. It was early registration so I anticipated that I would be getting the exact schedule that I had already made for myself.  BOY WAS I WRONG!! About a week before I was scheduled to register, I looked up all the classes that I needed to take and choose times that work with with my schedule (it was perfect). I already explained to my manager that I would be returning to school in the spring and that I also wanted to keep my job.  He said  "whenever my classes were, he would work around them" OK Kewl. NE way Early registration began on 11/13 @ 12:00 AM.  Because I'm able to register online, I was sitting in front of my computer at 11:50PM, waiting... When the clock struck 12 I entered my CRN's (Class Registration Numbers) and clicked submit.  I got swindled.  it wasn't even 12:01 and two of the classes I was registering for were already full.  Now I find myself waiting again for responses from teachers that I emailed asking for a manual override.  The situation sucks because there is no guarantee that I will get exactly want, Even after all the preparation that I had done.  This situation just shows me that no matter how much you prepair, their are always unseen and uncontrolable elements that can really mess up a good plan.  My only question is... How do you plan for incidentals? Or I could just forget about making plans and deal with every situation as it comes.