It’s considered one of the most selfless acts in the entire Harry Potter universe. As the Second Wizarding War breaks out all over Great Britain, Hermione Granger, Ron Weasley, and Harry Potter set out on a quest to find and destroy the Horcruxes Voldemort created to make himself invincible. But right before they do, Hermione pulls out her wand, points it at her parents, and casts a spell that erases all memory of herself from their minds. It’s an impossibly tough decision, and it comes with many moving parts. Why did she do it, and more importantly, did she ever reverse it?
Before we answer that question, we have to address one major detail.
The difference between the books and the films
The first three Harry Potter films were as close to the books as any Potterhead could ever hope for. This was of course due to the sheer size of the books. Sorcerer’s Stone, Chamber of Secrets, and Prisoner of Azkaban were all reasonably sized, with just enough detail to squeeze into a two-hour film. However, when Goblet of Fire was released at a whopping 636 pages, gone were the days of being able to include every last detail (lest we forget Winky the house-elf?). Alterations had to be made going forth, but with J.K. Rowling always in the writing room, fans could rest assured that all the important details would be included, or at least not messed up cataclysmically.
Why do we mention all of this? Because the spell Hermione casts at the beginning of the Deathly Hallows movie, right before she, Ron, and Harry set out on their quest for Horcruxes, is perhaps the biggest difference from the books. It makes you wonder: how did J.K. Rowling let that slide?
The spell Obliviate, which you hear Hermione say in the film, does as the word implies: it erases the person’s memory of whatever it is the spell-caster wants them to forget. It does not alter a memory ⏤ it removes it completely. Destroyed, gone, kaput.
While it may be possible to retrieve those memories (although not guaranteed), if cast by a powerful and intelligent witch like Hermione, Obliviate would remove the memories permanently. Was that Hermione’s intention, to erase herself from her parents’ memories permanently?
No, it wasn’t. As stated by Hermione in chapter six of The Deathly Hallows:
“I’ve also modified my parents’ memories so that they’re convinced they’re really called Wendell and Monica Wilkins, and that their life’s ambition is to move to Australia, which they have now done.”
Harry Potter and the Dealthy Hallows, page 96.
As you can see, Hermione’s intention was never to remove herself from their memories entirely, but rather to make them believe that they were completely different people. To her, this was safer than creating a gaping hole in their minds.
Why Hermione wiped her parents’ memories
It goes without saying that Voldemort and his Death Eaters have no moral boundaries. They’d stop at nothing to get what they wanted, even if it meant murdering and torturing Mr. and Mrs. Granger. Hermione, having the foresight she’s known for, put herself ⏤ and her parents ⏤ three steps ahead of the problem.
If the Death Eaters came a-knockin’, Mr. and Mrs. Granger would be gone and there’d be no way for them to torture the whereabouts of Harry (aka Undesirable No. 1) out of them. This was a bold, brave, and devastatingly sad move on Hermione’s part, but like always, it was the smartest decision she could have made and ended up saving the trio from getting caught.
Did Hermione restore her parents’ memories?
When the Second Wizarding War ended and Harry finally vanquished Voldemort, the first piece of business was no doubt attending to the fallen loved ones, like Colin Creevey, Fred Weasley, Tonks, and Lupin, among others. But once the dust settled, as J.K. Rowling stated in a webchat from 2007, “Yes, [Hermione] brought [her parents] home straight away.” Wendell and Monica Wilkins were free to be Mr. and Mrs. Granger again and were no doubt proud of their daughter. After all, it’s no exaggeration to say that without Hermione, Harry ⏤ and the Wizarding World at large ⏤ would never have been able to pull it all off.