Blood Marmite...I like it. You could put it on black pudding, while drinking Bull's Blood.

I think there's a distinctiion between natural thread drift, which can come in any threads - for example one song leads to another etc - and the kind of thing Russ is pointing out as a problem.

I like the jokeyness, except when I don't. It's all a matter of how your funny bione is articulated. (I tend to agree with what CS Lewis once wrote about facetiousness being a substtute fr humour rather than a variety of humour, in which people talk about something as if it was funny without having gone through the process of saying anything funny about it in the first place.)

But it doesn't have to be a choice between jokes or discussion/exploration. You can have both at once. You can put in a joke, or a crack about, for example something someone has said that might have a meaning they hadn't meant it to have - and in the same post you can try to carry the topic of the thread forward.