I don't suffer fools gladly!

I loathe that expression, don't you? It popped up recently and, rather than poke the protagonist in the eye with a blunt instrument, I took the time to ask for clarification.

You see, I was recently coaching a candidate on his interviewing skills and had asked how he might answer that hairy old chestnut 'what are your weaknesses?' A pause, followed by a triumphant 'I don't suffer fools gladly'. I asked him to define 'fool'. 'Someone who makes a stupid mistake,...