translation.en: And what went through my mind was, how often is it that teachers are thanked by their students for teaching them variables?  It doesn't happen in most classrooms, but that's because in most classrooms, when kids learn about variables, they don't know why they're learning it.
translation.zh: 那时我心想， 作为老师，因为教会学生变量而被感谢的 机会有多少？ 这在大多数课堂中都不常见， 但那是因为在大多数课堂中，当孩子们学习变量时， 他们不知道为什么要学这些。