Heron described my previous post as being
Rather like a long example and somewhat odd example of that old surrealist game where each person writes a paragraph after only seeing one line of the previous person's paragraph
My first thought was that a lot of internet conversations are like that. Email's particularly bad, because you frequently don't have any memory of the long history of the conversation you're engaged in, just the text in front of you. This can lead to serious conversation drift, as each response takes something in the previous mail and runs with it, paying little heed to the direction the conversation had been going in so far.
And then I realised that this wasn't purely a net-based phenomenon. I've been in several conversations where someone responded to some word or phrase and then based their response entirely on that. I've done it myself, picking holes in the grammar or metaphor rather than in what they meant, purely because it was what stood out from the conversation. I think that people's internal comprehension centres find it easier to snag a keyword or keyphrase out of the air and use it as the basis of their conversation than to understand and analyse the meaning of the whole conversation, produce a coherent response and then articulate it.
And that's why you get conversations like this:
Me: "and the other annoying thing he does is go on about the weather!"
Them: "The weather! Gaah, have you noticed how cold it is today. I wish I lived somewhere warm like California."
Me: "I spent 2 weeks in California once, travelling from San Francisco to Los Angeles, then on to Dallas to visit a friend."
Them: "Dallas, now there was a show. I remember those terrible haircuts, and JR being shot."
Me: "I'll tell you who I'd like to have shot, Bob in accounts."
Them: "Don't talk to me about accounts, why just last week....."
Each sentence doesn't require the participants to recognise more than 2 words in the previous one to reply to it and it almost sounds like they're listening to each other. But not quite.