"I and you": Correct or Not?

Eugene Volokh wrote:

1. I was recently reminded about the claim that "I and you" or "me and you" are grammatically incorrect -- not because "I" is being used instead of "me" or vice versa, but because it's wrong for "I" and "me" to go first. (Here's one sample I just found online, but I've seen others.) But that, it seems to me, is a principle of politeness -- let the other person go first -- and not of grammar.

Item 1 in the post is worth thinking about. I think it *is* a point of grammar, because I think grammar refers to the rules of speech that sound natural ("syntax", perhaps, if we're going to be precise).

"I and you know" grates on the ear as much as "I doesn't know". Since it distracts the reader or listener, it shouldn't be used except for a special purpose. An example of proper use might be:

"I learned that a long time ago. I have always believed it. I and you know that it's correct."

Even better, though, might be:

"I learned that a long time ago. I have always believed it. I-- and you-- know that it's correct."

What do you think?