|"Is this all real? Or has this been happening inside my head?"
The topic of this article is of a real-life subject that has been mentioned "in-universe" in a canon source. The Harry Potter Wiki is written from the perspective that all information presented in canon is true (e.g., Hogwarts really exists), and, as such, details contained in this article may differ from real world facts.
At least some content in this article is derived from information featured in Harry Potter: Magic Awakened, Harry Potter: Puzzles & Spells, Harry Potter: Wizards Unite, Harry Potter: Hogwarts Mystery.
Memories in the wizarding world
Extraction and external viewing
Memories can be extracted from a person's mind and reviewed, from an outside point of view, in a Pensieve. These memories appear as silver, hair-like wisps, and can be stored in bottles. Extracted memories can be altered, as Horace Slughorn attempted to do to a memory he gave to Albus Dumbledore in the 1996–1997 school year, although such alterations leave noticeable flaws in the recollection — this particular memory left sudden clouds with a booming voice in place of the crucial scenes; Dumbledore noted it was crudely done, so if done with more details and skills, a false memory may not be flawed. A fragment of Lord Voldemort's soul was able to show his memories through the power of his diary, rather than the need of extracting it and placing it into a Pensieve.
Once viewing the memory, the viewers cannot be seen or heard by anyone other than other viewers. What truly makes this phenomena remarkable is the fact that viewers can witness every aspect of the memory as they see fit from a third person perspective, even if the owner of the memory has little to no knowledge of what they are seeing, since one viewer was able to tail other people in the memory whilst the past version of the memory's owner was present at a fair distance away. The viewer is also intangible to all other physical matters and energies of the said memory, as Harry Potter was considered a phantom, invisible and intangible, to the rest of the past world he was viewing; a man shaking hands with Dumbledore went right through Harry's body, causing neither of them harm, and a later memory when Harry was phasing through many desks in the Great Hall while rushing to his past father's location, to which was described if done in the real world the desks would be sent flying.
Memories can be read without the needs of extracting them, through the powers of Legilimency; however, those that were extracted and then deposited into a magical device like the Pensieve or a simple vial can no longer be viewed through this manner. Also, Veritaserum works based on the memories of the person, and if there are any alterations done to such memories, they would speak what they assume to be the truth, not the truth that has been suppressed. Occlumency, the art of suppressing such memories and thoughts, is a way to counter the two aforementioned methods. A master Occlumens such as Severus Snape can choose what memories to suppress instead of completely blocking out Legilimency, so as to prevent the opposition from knowing crucial information without knowing that they are blocking it out on purpose.
External interference and damage
Memories can receive external interference such as the Memory Charm or False Memory Charm, which can suppress certain memories or create fake ones, respectively. Such alterations may cause permanent memory damage if done at a great intensity or incorrectly, as Gilderoy Lockhart and Bertha Jorkins both suffered severe amnesia that was irreversible. When Lord Voldemort forcibly broke through the Memory Charm on the latter, she remembered all of the things that were suppressed, but at the price of her body and mind suffering damage far beyond repair. Such alterations can also be bypassed such as when Dumbledore extracted a true memory over a false one in Morfin Gaunt, though he noted it to be a difficult task.
It is possible for someone to modify their own memories, both to prevent other people from learning the truth and to give themselves a sense of false comfort, as Horace Slughorn did to himself to spare himself of the guilt of giving Voldemort information on Horcruxes. Unlike being modified by others, the person can still recall the true memory that is suppressed under the false, although Slughorn's attempt was done rather crudely, in which periodic gaps where a thick smokescreen and his own booming voice took over the true scenes, which Dumbledore notes the true memory is still accessible by Slughorn. In terms of a self-modified memory, it becomes somewhat congealed and difficult to pour out of a vial.
- Tom Riddle's memory that he showed Harry Potter regarding the opening of the Chamber of Secrets in 1993. This was shown through the power of a diary horcrux.
- Albus Dumbledore's memory of the trial and sentencing of Barty Crouch Jr and the Lestranges. Viewed by Harry Potter in 1995.
- Albus Dumbledore's memory of Bertha Jorkins.
- Harry Potter's various memories. Viewed by Severus Snape through legilimency in 1996.
- Severus Snape's memory of when he was being bullied by the Marauders in his fifth year. Viewed by Harry Potter in 1996.
- Albus Dumbledore's memory of Sybill Trelawney's Prophecy concerning Harry Potter and Voldemort.
- Bob Ogden's memory of the Gaunts. Viewed by Harry Potter and Albus Dumbledore in 1996.
- Albus Dumbledore's memory of meeting the eleven year old Tom Riddle. Viewed by Harry Potter and Albus Dumbledore in 1996.
- Morfin Gaunt's memory of meeting the teenage Tom Riddle for the first time. Viewed by Harry Potter and Albus Dumbledore in 1997.
- Hokey the House-elf's memory of Hepzibah Smith and Tom Riddle. Viewed by Harry Potter and Albus Dumbledore in 1997.
- Albus Dumbledore's memory of Tom Riddle's unsuccessful job interview for a teaching position at Hogwarts in Defence Against the Dark Arts. Viewed by Harry Potter and Albus Dumbledore in 1997.
- Horace Slughorn's memory of when he explained horcruxes to Tom Riddle, first the crudely modified and then the real, undiluted one. Viewed by Harry Potter and Albus Dumbledore in 1997.
- Severus Snape's memories regarding himself and Lily Potter. Viewed by Harry Potter in 1998.
- Multiple exchanges between the minds of Harry Potter and Lord Voldemort.
- Sometime in the 2010s, a member of the Statute of Secrecy Task Force discovered a long-lost phial with a memory belonging to Alberta Toothill, featuring her 1430 victory of the All-England Wizarding Duelling Competition.
- Amata in The Tales of Beedle the Bard cast the memories of her lost lover into a stream.
Behind the scenes
- When Riddle manifested from the diary horcrux, he claimed to be "a memory, preserved in a diary for 50 years". However, due to his ability to think for himself and create a semi-corporeal form via sapping Ginny Weasley's life force, Albus Dumbledore suspected against this, as no mere memory can achieve such a sinister and complex effect. The soul fragment only told Harry Potter that it was a memory to preserve the secrecy of his origin's immortality.
- Harry Potter and the Philosopher's Stone (First mentioned)
- Harry Potter and the Chamber of Secrets
- Harry Potter and the Chamber of Secrets (film)
- Harry Potter and the Chamber of Secrets (video game)
- Harry Potter and the Goblet of Fire (First appearance)
- Harry Potter and the Goblet of Fire (film)
- Harry Potter and the Order of the Phoenix
- Harry Potter and the Order of the Phoenix (film)
- Harry Potter and the Order of the Phoenix (video game)
- Harry Potter and the Half-Blood Prince
- Harry Potter and the Half-Blood Prince (film)
- Harry Potter and the Half-Blood Prince (video game)
- Harry Potter and the Deathly Hallows
- Harry Potter and the Deathly Hallows: Part 2
- Harry Potter and the Deathly Hallows: Part 2 (video game)
- Harry Potter and the Cursed Child (Mentioned only)
- Harry Potter and the Cursed Child (play) (Mentioned only)
- Fantastic Beasts and Where to Find Them: The Original Screenplay
- Fantastic Beasts and Where to Find Them (film)
- Fantastic Beasts and Where to Find Them (Mentioned only)
- The Tales of Beedle the Bard
- Wizarding World
- J. K. Rowling's official site (Mentioned only)
- Harry Potter Trading Card Game (Mentioned only)
- LEGO Harry Potter: Years 5-7
- Fantastic Beasts: Cases from the Wizarding World (Mentioned only)
- Harry Potter: The Character Vault
- Harry Potter: Hogwarts Mystery
- Harry Potter: Wizards Unite
- Harry Potter: Puzzles & Spells (Mentioned only)
- Harry Potter: Magic Awakened (Mentioned only)
Notes and references
- Harry Potter and the Goblet of Fire, Chapter 30 (The Pensieve)
- Harry Potter and the Half-Blood Prince, Chapter 17 (A Sluggish Memory)
- Harry Potter and the Half-Blood Prince, Chapter 23 (Horcruxes)
- Harry Potter and the Chamber of Secrets, Chapter 13 (The Very Secret Diary)
- Harry Potter and the Order of the Phoenix, Chapter 24 (Occlumency)
- Harry Potter and the Order of the Phoenix, Chapter 28 (Snape's Worst Memory)
- Harry Potter and the Order of the Phoenix, Chapter 37 (The Lost Prophecy)
- Harry Potter and the Half-Blood Prince, Chapter 10 (The House of Gaunt)
- Harry Potter and the Half-Blood Prince, Chapter 13 (The Secret Riddle)
- Harry Potter and the Half-Blood Prince, Chapter 20 (Lord Voldemort's Request)
- Harry Potter and the Deathly Hallows, Chapter 33 (The Prince's Tale)
- Harry Potter: Wizards Unite (see video)