People believing themselves to have an accurate and undisputed overview of a subject, which is in fact a thoroughly unrepresentative cross section that they have mistakenly elevated to the status of Revealed Truth. I used to think that the world was divided into details people and big-picture people, that I was firmly in the former camp, and that I therefore ought to listen respectfully to people in the latter camp because I needed their input to get certain sorts of thing done. I am now coming round to the view that in fact rather too many of the people in the latter camp are woolly-thinking, conclusion-jumping guesswork merchants to make this a dependable life strategy.
When I have a thought that feels like a big-picture insight, I have a healthy doubt of its universal applicability, and am therefore hesitant – perhaps overly hesitant – to noise it about until I'm really sure. And even then, I tend to start by saying ‘hmm, I wonder if’. Some other people seem to lack that doubt, which can make them sound interesting and incisive and highly synthetic … until one day they make a sweeping statement with their usual confidence and flair and you happen to know from personal experience that it is absolute drivel. And then you wonder about all the other things they've ever said in that tone of voice, and worry that you might have let a quantity of comparable drivel influence your thought processes without realising.
Stamp-collecting overviews of a topic. If there's one way to explain a subject area to me which is guaranteed to leave me with the feeling that I've been told everything except what I really wanted to know, it's to list a lot of bits and pieces and not give an idea of how they all relate to each other.
Don't just tell me there are three schools of thought on a topic, for instance. Tell me whether they occurred at different points in history and superseded each other in a clear order; tell me whether any of them produced clear demonstrations that one of the others was untenable; tell me whether people's adherence to them correlates to any other relevant factor in their opinions or attitudes; tell me which, if any, is generally believed today and whether the reasons why look like changeable fashions or like genuine advances of understanding. And don't tell me there are five different ways to make a widget and then just list them with a brief description; tell me why I need to know that, such as what each one's advantages are compared to the others and why everyone hasn't just settled on a single one. Otherwise I will feel you haven't explained anything at all, you've just read out the sales catalogue.
The style of argument which involves waiting for the other person to make a definite statement, and then contradicting it without providing any counter-statement. If you've got all the answers, be so good as to share one or two of them with us; or, failing that, it's only fair for you to at least make some kind of a statement so we can have a turn at putting you down. Even Kosh didn't get away with this in the long run, and neither will you.
(Disclaimer: Each of the above annoyances is derived from accumulating a large number of specific experiences and noting what they had in common. It's possible that some people reading this might have done some of these things on occasion; but if anyone thinks one of the above rants is directed mainly at them, it isn't.)