So I am a big believer in God, and that everything (good and bad) happens for a reason. Sometimes your plans can change at the last minute, but sometimes that is not necessarily a bad thing!
For example: I had spent quite a few hours dissecting my summer and fall class schedules. I carefully planned the timing of each class, the number of credit hours I was taking, which classes were requirements and which were just for fun, etc. I had accepted the fact that I didn't get into one or two classes over the summer that I REALLY wanted to take and are not offered very often, and had tailored my schedule just so.
All that changed when I found out that even though I was on the waiting list for one of the summer classes I really wanted to take but wasn't planning on taking, I got in!!! So now I had the option to take Bookbinding. The problem was that this messed up all my other credit hours for summer AND fall, and so I had to change my schedule around again! I did this, then found out that I got into ANOTHER class for summer that I didn't think I was going to get into! So I changed my schedule AGAIN! :)
All of that to say that sometimes even when you think you are totally in control, it is interesting to have those moments where everything you have carefully planned gets thrown in the trash in a second to make way for plans that are so much better than you could have ever imagined for yourself :)