interesting point....could the same said about horror, whether it be in films, stage or books etc? If the only true humour is spontaneous, isn't that also true of the only real horror? Everything else is utterly predictable, staged and even rehearsed, so why would it be scary?
In defence of comedy, you are right to a large extent about sitcoms, tho one can find humour in things that are predictable, indeed, the anticipation of a punchline can lend ift even greater humour. For some stand up comedians, large chunks of the act is off the cuff, and depends entirely on what the audience give them to work with (a great exponenent of this is Dara O'Briain). For me, much of this type of humour is the funniest of all as it depends entirely on quick wit and clever use of words, so Iguess I do agree, to an extent with you. But I absolutely love stand up comedy, it's my favourite form of entertainment.