"Us neither" - Is it valid?
Recently, I read the phrase "Us neither", and for some reason it irked me. I don't know why though, since I can't immediately say what exactly is wrong with it. Logically, "Me neither" and "Neither have I" are equivalent, so why would "Us neither" not be similar to "Neither have we"? No matter how I try though, it just sounds wrong.
Is there are reason that it sounds so awkward to my ears, other than that I'm just not used to it?