I didn't understand the argument in the leaked ep

When Percy and Annabeth are arguing about keeping secrets, I don't understand why Annabeth suddenly bursted out a 'I didn't like middle school/movies' thing that her and Percy mentioned in s1. I get that her point was that they are not the same as she is just a demigod and he isn't, but why mention that when he's mad about her keeping secrets? And what was the whole point of the 'everything becomes less scary when you talk about it', and Annabeth saying 'it's about to get more scary.'? I'm confused how they got to that point in the conversation when Percy's original argument was that he didn't get chosen for the quest and feels like Annabeth's keeping secrets from him?

Imo the argument was well written and it was played out well but I'm just slow y'all 😭 I need someone to break it down for me since there's more emotion here than the books