Knitting blindness (or, facetious builders)

Have just had the following conversation with the Facetious Builder:

FB: What are you knitting?
Me: A cardigan (holding up the completed back section of my Tailored Scallops cardie)
FB: Looks exactly the sam as the one you've got on (my Notre Dame de Grace pullover)
Me: OK... that one's pink; this one's orange. That one's got a wavy pattern; this one's got straight lines. That one's a cardigan; this one is a pullover. I could go on.
FB: oh. Ha ha ha.

Jebus christ almighty but he does my freakin head in.