I got given a load of pieces of pot to talk about in my interview and I noticed one of them looked a bit odd. I then talked about this bit for about five minutes saying how rough the clay looked, lots of inclusion, quite primitive etc.. then suddenly realised it was a block of cement - apparently it was a bit of the Berlin wall and what I thought was some wierd matt glaze was actually spray paint! there was even this white dribble which I blathered on about as 'evidence' for artistic/decorative techniques. I felt soooo stupid!
Sorry, to the normal sane person not obsessed with classical archaeology this must seem terribly trivial!