QI is a great show, although it can really make one feel stupid for pointing out that the things one knows as fact, are actually entirely inaccurate...
If Stephen Fry asked me what 4+4 was, I'd know it's definitely not 8.
The answer is never the answer. Never answer with the answer!
The worst part is, that every once in a while they do a double tricking, and then the obvious answer is actually the answer. You're never safe from looking a fool on that show!