10 Famous Movie Plot Holes (That Are NOT Plot Holes)
2. The Time-Turner - Harry Potter & The Prisoner Of Azkaban
In Harry Potter and the Prisoner of Azkaban, Hermione and Harry use a Time-Turner to travel back in time several hours. As soon as this time machine was introduced, many viewers pointed out that Harry should've used it to stop Voldemort from killing his parents when he was a baby. (I mean, why would he choose to save Buckbeak but not his Mum and Dad!?)
You know who didn't complain about this scene? The people who read the book! Do you know why?
Because it is explained in the novel that Hermione's Time-Turner can only go back several hours and can't return the user to their original timeline. There are other Time-Turners that allow the user to go back much further, but they are off-limits to students (and nearly all of them are destroyed by the seventh book).
Even if Harry got his hands on a more powerful Time-Turner and used it to stop his parents from being killed, he would be trapped in that timeline.
As horrific as it was for Harry to lose his mother and father, he needs to accept it, since altering the timeline so drastically could end up making things worse.