Time well spent, but at the wrong time

I was expecting to take two tests this weekend over music history and theory as entrance exams into masters programs. I planned on my talent for theory to do well on that exam, and spent 25+ hours studying music history. Come to find out that I'm not taking the history exam this weekend, but at a future date. That means that I should have been studying theory for 25+ instead of history, and then rocked the exam. Oh well, when I do take a history exam, at least I'll be ready.