"Which is why it’s a good thing I brewed a cauldron of  Felix Felicis  right after the Battle of Hogwarts and still have a few phials at my flat," Hermione said with a smug smile. "I couldn’t make any while we were on the run, but I would have loved to have some when we got back to the school. So when Voldemort disappeared again, I thought it would be a good idea to have some on hand for the next time we had to face him." She shrugged. "I nearly ruined it at the five-month mark too, and let me tell you how annoyed that would have made me."