How we cite our quotes: (Act.Scene.Line)
Quote #7
PROFESSOR McGONAGALL: And your response to disappearing Hugo and Rose Granger-Weasley was to go back in time again—and this time, instead of losing two people you lost a huge number of people and killed your father—and in doing so you resurrected the worst wizard the world has ever known and heralded in a new age of Dark Magic. (3.10.4)
Thank Dumbledore that McGonagall is around to discipline Albus Potter. If it were left to Harry, he'd probably tell Albus how cool it was the time he went back in time and saved his godfather.
Quote #8
ALBUS: The stupid thing wasn't going back once—anyone can make that mistake—the stupid thing was being arrogant enough to go back twice. (3.14.22)
Being able to return the past is an alluring prospect. That is why we have so many movies and TV shows about time travel. It's irresistible. Albus and Scorpius have to go back—and screw up—twice before deciding to not to do again. And even then, Scorpius doesn't destroy the Time-Turner right away.