New member urgent question

Ok so I've been friends with this guy since last August. When I first met him we instantly clicked we would have conversations for up to 4hrs it was almost as if he memorized an encyclopedia he's a freaking genius. But I started picking up on things like he'll insert strange details into stories (which he repeats) like the exact time the weather to the point where 3hrs have gone by and he's still on the same story. If anyone has seen the movie Rain Man he acts almost EXACTLY like Dustin Hoffmans character. Latley he's been pacing back and forth obsessively scratching his head repeating the SAME stories like a broken record. Is it possible he's like an autistic savant or someone with severe asbergers? PLEASE ANY INFO/ADVICE

Can you tactfully ask him? About just one aspect of this behaviour, perhaps.

In what way is it causing a problem for you?