One possible reason could be that he had a traumatic event related to dirt or mess in his past. Maybe he witnessed something really bad in a dirty place, and now cleaning helps him feel in control. For example, if he saw a death or a fight in a filthy alley, the act of cleaning could be his way of erasing that memory symbolically.
One possible reason could be that he has experienced a lot of chaos in his life and cleaning gives him a sense of control. For example, his adventures in the wizarding world are full of danger and unpredictability. Cleaning allows him to create an orderly space in the midst of all that turmoil.
His friends might find it a bit odd at first. Some of them could be put off by his constant need to clean. For instance, Ron might not understand why Harry is always tidying up their dormitory and might feel like Harry is being too fussy. However, others like Hermione might appreciate it as she also values order and cleanliness.
In a fanfiction, Harry might have a cleaning habit because it helps him relieve stress. After a long day of dealing with Voldemort or difficult classes, he would retreat to his room and start tidying up. He might even start a little cleaning club at Hogwarts, where students come together to keep the school clean in a fun and magical way. For example, they could use brooms that sweep by themselves and mops that dance around the floor to clean it. This would also be a great way for different houses to bond over something other than Quidditch.
His friends' reactions would be an important part. Some might find it odd at first, but then they come to appreciate how clean their shared spaces are. Ron might be a bit lazy about cleaning at first but then get inspired by Harry. Hermione would be proud of Harry's organized and clean living environment and might even help him come up with more efficient cleaning methods using magic.
Some characters might find it odd or annoying at first. For instance, his friends like Ron and Hermione could be initially puzzled by this new behavior. Ron might make jokes about it, while Hermione could try to analyze it from a psychological or magical perspective.
One possible reason could be the pressure of Harry's fame. In the wizarding world, he's a hero, and that comes with a lot of public scrutiny. Ginny might find it hard to deal with all the attention on their relationship. Another reason could be differences in their future plans. Maybe Harry wants to focus on his Auror training and Ginny has her own Quidditch career goals that seem to conflict.
One possible reason could be that he might be facing some personal issues or traumas. For example, he could have had a bad experience in a previous competition that made him afraid to compete again. Another reason might be that he has some moral objections to the nature of the competition. Maybe he believes it's unfair or goes against his principles.
One reason could be extreme stress. In fanfiction, Harry might be facing a new and overwhelming threat, like a powerful dark wizard that even his skills can't easily handle. The pressure of having to protect his friends and the wizarding world could cause him to faint.
One possible reason could be extreme depression. Maybe in the fanfiction's plot, Harry has faced so many losses and hardships that he feels there is no way out. For example, if all his friends turn against him or he fails to achieve his goals repeatedly.
Well, in some versions of the 'Dursleys abandon Harry fanfiction', they abandon him due to social pressure. They are worried about what their neighbors or friends might think if they find out about Harry's true identity. Also, Petunia may have some deep - seated jealousy towards her sister Lily for being a witch, and this negative feeling extends to Harry, leading them to abandon him.