Exactly the same thing happened to with Meteorology!! This subject has always been of interest to me, and I got a bit blase. I thought I knew it all, and it turned out I didn't!! Failed first time with 70%. I was gobsmacked, and spent the next two days really going to town with the subject books, and passed with 100% just 48 hours later!!
Now to the flying bit - I'm still waiting to do my final landaway and then the QXC. Every time I'm booked in, the weather cans it. I'm booked again for both tomorrow and Tuesday, but the weathers looking iffy all week. If I can't get the next one by Thursday 8th, I've run out of solo landaway currency, so have to do a local landaway again with an instructor. It's really frustrating. Bad time of the year I guess.....