A vague one from me. A few years back Bob Hoskins did an ad for, I think, whisky. He was asking questions, and a duck answered with 'I don't know, I'm a duck'.
I'm trying to remember the scenario of the ad.
That's it!! I remember the pig walking past in the ad. Thank you.
I'd love to see it again..my hubby has..for a few years, answered any questions, he can't answer in work, with that phrase...and all of a sudden, it seems to be catching on...someone asked him the other day, where the saying came from.