For me personally, I do a lot of things that others find rude:
• No eye contact
• Slurp on my food (any child does that, like leave them alone, they just want to eat!)
• Slouch (hey I’m always tired, ok?)
• Burp and/or fart (I get it, it’s gross, but that’s how the human body works)
• Leave the room in the middle of a conversation (I just have to walk away, because things can be overwhelming)
Those are just a few that I can think of. I know I might have a lot more that I haven’t thought of, and I don’t want to waste a lot of time on this, so I’ll just leave it there.