Hermione found out that she had been checked into St. Mungo’s with something called  magical exhaustion, a malady that affected witches and wizards who had tapped too deeply into their own magic; hers was a particularly bad case, they told her. Her connection to magic would need months—perhaps years—to fully recover. She would need to relearn the most basic spells, and build her way back up to her previous level of magical ability. 