Thinking. John has some incredibly strong characterization as a child, especially regarding his relationship with his father. This especially comes up in the assumptions Egbert tends to make about him. He's still at a point in his life where he doesn't quite understand his father as a human being, so everything about him is inexplicable.
Dad Egbert is just a plain, traditional man. He's a single father trying desperately to raise a child he does not know how to connect to in the slightest, and working an office job to support his two-person suburban family. But in John's head, he's this wild, zany character. Dad's like Superman, except instead of a superhuman alien disguising himself as an unassuming civilian reporter, it's a street performer disguising himself as the world's most White Father ever all the time. Never does John ask himself if that makes literally any sense because he's a Child. Child Brains Don't Make Sense.
I have to point out how much Dad Egbert is a force of Traditional Masculinity, though. There is, as well-meaning as Dad is, still a vague aura of oppression in the Egbert household just due to how intensely Dad embodies the role of a Patriarch. Every single scrap of text we see from or about Dad emphasizes Masculinity as a construct. Particularly, John's "necessary" evolution into Manhood is something that is repeatedly stressed in, like, every note Dad has left for John.
And... There's a lot of things one can say about John's feelings about Dad, particularly regarding the obvious intense frustration John feels about him.
Rose is a terrible source for literally like any information, especially information regarding her friends, but this frustration is tangible in the preceding text. This is a rare Rose Not-Bullshit Moment. The way John rejects his father - for example, for Dad baking John a lot of sweets on his birthday - does speak to some kind of pent-up frustration... As well as general Teenage Moodiness.
Those feelings have been a point of debate over the years, I've seen. A lot of the time, people tend to be asking why John seems to feel so negatively about Dad when he seems to be an alright guy. Usually the answer reached is either "John's just being petulant because he's 13" or "Dad Egbert is secretly super abusive", but like... Honestly, I think the intense gendering is exactly it. It's not necessarily that Dad's doing a terrible job at raising his son, it's that he doesn't recognize he's raising a daughter. And neither does she, but she still isn't happy about it, you know? That feeling of wrongness is still there. The hurt is felt, whether or not she knows why.