It is how we suss out where someone is coming from. How they are feeling; or what sort of person they are. And, depending on how well we know someone, the jokes can be subtle, to downright rude.
But not to the intolerant youth. More and more, any kind of joke will fall flat, and I have figured out what it is.
Yes, I can now tell you what the problem is - and it is not you. Except, perhaps, that you had the audacity to get old. Well, survive to over 40, that is.
You see, humour depends on shock value. An unexpected ending. A logical but absurd conclusion. A truism taken to a predictable, but painful end. No one really knows what makes humour funny, but I think you get the picture.
Now, enter the young. Those we have willingly sent to be corrupted in our schools. To be made "politically correct" by earnest young school teachers, who themselves were moulded this way by university professors who harbour more hidden agendas than an old Kremlin Politburo meeting.
The young have been taught to weigh each statement to judge for themselves whether it passes the acceptability test. To hold each sentence up to the template of political correctness. To make a judgment: Will it denigrate anything the proletariat value; is it going to offend?
Humour depends on the absurdity of the moment - the snap realisation of what has been said. A good joke brings in logic, references and truisms that must be processed in a split second if they are to be funny.
When everything that is heard must be processed in this dreary mill of Marxist thought, the moment has gone. The joke falls flat at the feet of the intolerant youth.
Over time, no one will expect to be entertained by wit or banter, or to see "the funny side" of things; it is no longer worth the effort. Paradoxically this has meant the re-emergence of slapstick humour: the slip-on-a-banana-skin/bucket-of-water-over-the-door type of joke. At least children find it funny.
So where was I? Oh yes. Well, there was this geriatric one-legged Islamic Scotsman, an Irish whale hunter, and a red-haired Maori lesbian SIS spy, and they all walk into a bar hand in hand ...
Chris Northover is a former Wanganui lawyer who has worked in aviation, tourism, health and the environment - as well as designing electric cars and importing photo-voltaic panels.