Perhaps in this fanfiction, Harry loses his family's legacy. For example, something might happen to make people believe that his parents were not the heroes they were thought to be. This would not only shatter his own self - image but also make him lose the respect and support he had from the wizarding community. It would be a huge blow and make him feel like he's lost everything.
There might be a new dark wizard or witch that we don't know in the main series. This new character could be extremely powerful and target Harry specifically. They might have a vendetta against Harry's family or just want to take over the wizarding world by first destroying Harry, who is seen as a symbol of hope, and thus make him lose everything.
In a 'Harry Potter Lost in Space' fanfiction, Harry might use his magic in unexpected ways. For example, he could use the levitation charm to move around in zero - gravity. His wand might also be affected by the space environment, perhaps glowing differently or having new powers.
Well, it might be that Harry is lost at sea due to some sort of magical accident. He could meet other magical beings that are native to the sea, such as mermaids. They could either help him or pose a threat. And perhaps he has to find a way to use his Hogwarts - taught magic in new and creative ways to get back to land. He could even discover some long - lost magical artifacts at the bottom of the sea.
Well, perhaps in the 'Harry Potter finds a lost library' fanfiction, the library is magically protected. Harry could encounter some magical creatures that are guardians of the library. He might also use his Parseltongue ability to unlock a special part of the library, leading to a discovery that changes the course of his fight against the Dark Arts.
In this kind of fanfiction, Harry might feel extremely lost and depressed. He has been defined by his magic for so long, and without it, he'd have to re - evaluate his identity. Maybe he'd start to rely more on his friends, like Ron and Hermione, in different ways. For example, instead of using magic to solve problems, he'd have to use his wits and their combined non - magical skills.
It could be a hard and challenging one. He might have to start from scratch, face lots of difficulties, and find the strength to rebuild his life.
Well, in fanfiction, when Harry lost his glasses, it could potentially change the course of an adventure. He might not be able to see magical creatures or signs clearly. This could lead to him making mistakes or getting into trouble that he wouldn't have if he had his glasses. He could accidentally walk into a restricted area or misinterpret a magical symbol, all because he can't see properly without his glasses.
Maybe he was hit by a powerful dark magic spell specifically designed to target the soul. Such spells in the Harry Potter universe can be extremely dangerous.
He might encounter magical creatures that are native to the forest. For example, he could come across a group of centaurs. Centaurs in the 'Harry Potter' world are known for their wisdom and their own set of rules. They might either help Harry find his way out or be indifferent to his plight depending on how Harry approaches them.
She could end up in the wrong part of town. Maybe she was supposed to be at a library but ended up near a noisy construction site because she couldn't read the street signs clearly without her glasses.