"You are welcome" + Rule of Three (1819)

[Mark A. Mandel]

Duane Campbell <dcamp at CHILITECH.NET>:
>>>
I had a German friend whose English was minimal, at best, but that didn't
prevent him from using it, sometimes incomprehensibly. If you said, Thank
you, he would reply, "Shut up."  What he meant was, "Don't mention it," but
how he got from there to "Shut up" I never did figure out.
<<<

It seems simple to me:
        Don't mention it
                (as a literal imperative)-->
        Don't talk about it
                (taken more generally)-->
        Don't talk
                (disregarding register, which seems
                 plausible in this case)-->
        Shut up

-- Mark
[This text prepared with Dragon NaturallySpeaking.]