(Strip Number 604, Original Publication Date, 2 May 1984)
Panel 1: Now that Phil has finished giving Michael his first trumpet lesson, he hands him a book and tells him that he wants him to practice the notes C, D and E.
Panel 2: Phil then tells him that wants him to practice notes for at least half an hour a day.
Panel 3: Phil reminds Mike that practice makes perfect.
Panel 4: Elly frowns in despair because another fake hardship has been added to the laundry list of things that aren't actually unbearable torments and thought-bubbles about how it is nagging that makes practice happen in the first place.
Summary: What Elly loses sight of is that it's also nagging that makes children avoid practice. We are, after all, dealing with a stupid woman who only occasionally allows herself to admit that it was her non-stop criticism and dimwitted belief that praising a child made him spoiled ([Elly whining]He'll EXPECT IT!!![/Elly whining]) made Mike hate practice so very much.