The theme of Naruto's struggle with his own power and the expectations that come with it can be common. He might be quietly suffering because he feels pressured to always use his power for the good of the village, but at the same time, he may have personal desires or doubts. In fanfictions, this can be explored in depth, such as when he has to make difficult choices between his own wants and the needs of the community, and how this causes him mental anguish.
Often, in these fanfictions, the theme of unrequited love and Naruto's silent heartbreak is present. Naruto has strong feelings for certain characters, but those feelings may not be reciprocated. This can lead to a great deal of internal suffering for him. It also shows his vulnerability, which is different from his usually strong and determined image in the original story. The fanfictions may focus on how he hides this pain from others while still trying to be the cheerful person everyone expects him to be.