I never watched Sheldon, but I get what you mean. I don't think I'm rude at least I don't try to be. When I was a kid my dad had to really drill it into my head that small things I do or don't do are rude. Still don't get why those things are rude I just do what he told me to do so people don't get fussy about it.
EDIT: My dumb ass thought you were talking about a show called Young Sheldon not the Big Bang Theory. Then I google Young Sheldon and find out its a Big Bang Theory spin off I'm just sat here "wtf" is all I can really think at this point.