Posted by Andrew Craig-Bennett on November 25, 2006 at 14:01:22 from 81.144.214.226 user ACB.
In Reply to: Teach Your Grandmother posted by Ed Kiser on November 23, 2006 at 02:35:32:
Missee Lee would have known the expression, when used by Captain Flint, as "Ban men nong fu" (chopping wood outside Lu Ban's door - Lu Ban was a celebrated master carpenter). The meaning is precisely the same - the speaker is responding to being told something that he or she already knows perfectly well.