Autism

I have a little brother that is on the spectrum and he is obsessed with meme culture and memes to the point that he cares about nothing else. He can't talk about anything else and always tries to say memes without context and understanding hoping to make us laugh. I would not have a problem with this unless it was not the only thing that came out of his mouth. I am worried about his future. He won't be able to live with just memes. He maybe sometimes plays minecraft and that is the only creative thing he does. He is great but he will do some pretty upsurd stuff like, he will avoid his friends just because they bought a memed soft drink. He hates talking unless it is memes. He doesn't like questions. He hates thinking. What do I do? I literally can't connect with him. Once I will give him a piece of advice, like, "maybe find a better time to say the jokes so that they land better" and "please try not thinking about memes all the time" and he will say yes and proceed to ignore whatever I said.