It seems obvious to me when he outright mentions loving his great-grandfather's diaries and that the obsession didn't start until he moved in with his grandmoth

It seems obvious to me when he outright mentions loving his great-grandfather's diaries and that the obsession didn't start until he moved in with his grandmother. But yes, it's speculation. I would rather ask a lot of questions before showering a kid with positive attention for something that might have been an adaptation to an unhealthy relationship.