What a great quote by Hanon!
Here is the quote in its context. Notice the third to last paragraph. I love the irony that Hanon says, in essence, if you haven’t been practicing, you can play this book for “a few hours” and catch up. I’d love to tell my students, “Hmmm. It seems like you haven’t practiced this week. But good news: If you practice these exercises for three hours, you’ll be right back to where you were last week,”