There is a Plot Hole in Harry Potter Even J.K.Rowling Kinda Failed to Explain
The Wizarding World website tried, but fans still have a couple of questions about this one.
In the fifth chapter of the Harry Potter story, Order of Phoenix, Harry encounters for a first time with creatures he was not able to see before: Thestrals. In the magical world created by J.K. Rowling, thestrals are horse-like creatures that are invisible to people until they witness a death.
However, Harry's life was quite rich in incidents when he had to witness the death of people who were close to him or just fell victims to Lord Voldemort or his servants. After all, his story begins with Voldemort murdering his parents — something that had to grant him the ability to see thestrals from year one at Hogwarts.
According to the Wizarding World website, Harry "was unable to see Thestrals for years after his mother was killed in front of him, because he was barely out of babyhood when the murder happened, and he had been unable to comprehend his own loss."
But fans are not quite satisfied with this explanation, arguing that it still does not resolve the problem.
"I find it so odd that he can't see Thestrals but he can hear his mother's scream when Dementors are around since it's such a far off memory," Redditor Disastrous_Price5595 pointed out.
After all, Harry did have to "re-live" the experience in his third year when Professor Lupin was training him against Dementors, which would clearly help him comprehend the loss, other fans noted.
Still, only the death of Cedric Diggory triggers the mechanism that helps Harry finally see the thestrals who turn out to be living near Hogwarts and helping with the carriages. Meanwhile, Luna Lovegood, who was apparently capable of seeing them this entire time, lost her mother at the age of nine — an age that apparently already allowed her to comprehend the loss.
Rowling herself, however, has never accepted that Harry's ability to see thestrals in year five was a mistake.
"When you find out about the Thestrals, you find that you can see them only when you really understand death in a broader sense, when you really know what it means. Someone said that Harry saw Quirrell die, but that is not true. He was unconscious when Quirrell died, in Philosopher's Stone. He did not know until he came around that Quirrell had died when Voldemort left his body. Then you have Cedric. With Cedric, fair point. Harry had just seen Cedric die when he got back into the carriages to go back to Hogsmeade station," Rowling told fans at the Edinburgh Book Festival back in 2004.