Why do dementors attack Harry during the Quidditch match?
What provoked the dementors to attack Harry Potter?
Why do dementors attack Harry during the Quidditch match?
Well, dementors feed on the happiness of other people, and leave them with sad memories after they suck out all the happiness. Since everybody was cheering at that time and dementors thought for getting food, they left to attack during Quidditch match. However, they were not there to attack Harry only.
What provoked the dementors to attack Harry Potter?
Since Harry reached there first when dementors were coming, so they attacked him. Besides, dementors affect him very badly, more than anyone else.
Harry has very bad past. His parents were killed by Voldemort when he was 1 year old. He lived with his uncle and aunt who tortured him a lot.
Here is conversation between Harry and Professor Remus Lupin.
Harry: Professor, why do the dementors affect me so? l mean, more than everyone else?
Remus: Dementors are the foulest creatures to walk this earth. They feed on every good feeling, every happy memory until a person is left with absolutely nothing but his worst experiences.
Remus: You are not weak, Harry. Dementors affect you most because there are true horrors in your past.
Dementors: The dementors are a phantom species who, as their name suggests, gradually deprive human minds of happiness and intelligence.
In Prisoner of Azkaban, the dementors are attracted to the Quidditch match because of the huge crowd and the excitement in the air. Dementors look for happiness and suck out the happiness of a person.
The dementors reach the Quiddich match full of people, they were not particularly there for Harry, they were just there for everyone.
Why was Harry affected and attacked?
The dementors bring forth the darkest and saddest memories of a person and Harry had been through much more than most of the other students. So when the dementors were anywhere around Harry, he was affected the most out of everyone. Even more than Ron or Hermione or anyone else.
He had been through losing his parents, the abuse from his Aunt and her family and literally had not a single happy memory till he came to Hogwarts.
And since Dementors had the most to get out of Harry (due to his horrifying past), they were driven to him more than anyone for a soul-satisfying meal of Harrys happiness.