In some fanfictions, it could be due to a misunderstanding. For example, Percy might be involved in a quest where things seem a bit shady, and Annabeth misinterprets his actions as something more malicious. Also, the stress of their demigod lives could take a toll on their relationship. Constantly facing monsters and life - threatening situations can make them short - tempered with each other, and over time, it could lead to a break - up.
One possible reason could be differences in their long - term goals. Maybe Annabeth is more focused on her architectural dreams and wants to study in a far - off place, while Percy is more tied to the demigod world in Camp Half - Blood. Another reason might be jealousy. If Percy spends too much time with other demigods, especially female ones, Annabeth could feel left out and insecure, leading to the break - up.
Perhaps a prophecy comes into play. A prophecy that requires Percy to be alone or with someone else for the greater good of the demigod world. Annabeth, being the logical and selfless person she is, might decide to break up with Percy to ensure the prophecy is fulfilled and to protect the demigod community as a whole.
Perhaps Percy realizes that their relationship has become too codependent. He might feel like he's losing his own identity within the relationship. He could also break up with Annabeth if he discovers some long - hidden secrets about her past that he can't come to terms with, like if there were things she did in the past for survival during a quest that go against his moral code.
One possible reason could be differences in their duties. Artemis is a goddess dedicated to chastity and the hunt, while Percy has his own quests and loyalties in the demigod world. Their paths might have diverged so much that it led to the break - up. Maybe Artemis felt that Percy's presence was starting to interfere with her commitment to her hunters or her own divine responsibilities.
One reason could be Percy's constant danger - attracting monsters and putting Annabeth in harm's way too often. In fanfiction, authors might explore how this constant stress could lead to a breakdown in their relationship.
Perhaps it's due to the interference of the gods. The other deities might not approve of their relationship for various reasons. Maybe Zeus, fearing the power that could come from a union between Percy and Artemis, decides to put an end to it. In the world of Percy Jackson, the gods often meddle in the affairs of mortals and demigods, so this could be a factor.
In fanfiction, they might break up because of outside pressure. For example, if the gods or some powerful force tries to keep them apart for some reason. However, their strong bond and shared memories would eventually lead to their make - up. Their adventures together, like the time they spent in Tartarus, are so significant that they can't stay apart for long.
Perhaps jealousy plays a part. If Percy got a bit too friendly with another character, Annabeth might get jealous and they fight. However, they soon remember their strong bond and how much they mean to each other, so they make up. It's a common trope in fanfiction as it shows the depth of their relationship.
He could also become angry. Percy has a bit of a temper, and he might lash out at Annabeth, demanding an explanation. He might feel betrayed, especially if he doesn't understand the real reasons behind the break - up. In his anger, he could distance himself from their mutual friends and go on solo quests to clear his head.
Well, one possible reason could be that Percy made a really stupid decision without consulting Annabeth first. Like, if he went off on a dangerous mission on his own when they were supposed to be a team. Annabeth is a very strategic person and she might feel betrayed or extremely frustrated by such actions.
It could also be due to some sort of magic or mind - control. A powerful enemy might have cast a spell on Annabeth, forcing her to turn against Percy. In this case, it's not really her own will but the result of external manipulation.
In some fanfictions, Annabeth could abandon Percy because of a prophecy. If the prophecy seems to imply that being with Percy will lead to a great disaster, she might choose to leave to protect him or the world. Also, it could be due to a personal growth arc for Annabeth. She may realize that she has been too dependent on Percy in the past and decides to go off on her own to find her true self, leaving Percy behind.