I do think he probably has a receptive language disorder, which probably stopped him from learning in school. It could be perceptive as well,language is complicated in the brain. It’s clear from his language immaturity he is limited in what he had read, so he may well have a reading disability. Which is all part of language. Of course too. I’m not a doctor I’m not diagnosing him, I’m just an educated medical professional who has observed people like him with borderline abilities to function get lost when they don’t have an educated parent to guide them. He seems to have been left to his own devices to mis-function from childhood without parental correction or teaching him how to perceive the world around him, other than to be told he’s better than everyone , and people are mean to him because they are just jealous.
You don’t get kicked out of barns everywhere you go because you are so superior a person that others can’t allow you to outshine them, you get kicked out of barns because your social skills, judgment, behavior, and interactions with people are too disruptive to tolerate. Whoever ttaught him that he was great and other people were colluding against him did him no favors. He doesn’t have the skillset to learn from an experience and correct himself. The more people want to distance themselves from him, the more aggressive he gets insisting he deserves recognition. People just want to keep him away from themselves, their children, and especially their horses. Couple all that with his overt bigotry, and misogyny; his bragging about carrying guns, stalking and abusing women who stand up to him, and his sympathetic comparison of his self perceptions with what motivates mass shooters, and you have a real toxic animal no one wants to know.