So the other week I started teaching a course on how to perform basic statistical calculations on microsoft excel. I thought I had everything planned perfectly but no - a change in the college's IT setup meant that I was nearly completely screwed.
Thankfully I had pen drive and was able to sort out all the problems. I'm glad that I don't mind looking like an idiot in front of students.
I guess the thing here is that you can think you've planned properly and then something can still crop up that you haven't planned for. There was actually something I could have done to stop what happened but I didn't think of it beforehand.