That hoary old chestnut - and the fact I am considering whether to spell hoary that way underlines what an old chestnut this is - came up again last Wednesday during fervent discussion at an inner city cafe: men, says the chestnut, think about sex 1500 times a day.
Good grief, shouldn't there be a rule on urban myths?
Have the World Health Organisation not finally put this one to bed with authoritative research from both First, Second and Third World countries?
I sighed deeply when the chestnut rose again last week and yelped forth its mantra.
The ensuing conversation always follows the same path.
There is barely time for a pistol shot before another man will say, with questioning eyebrows, only 1500?
He will then retire triumphantly to the back of his chair with a metaphorical self-administered pat on the back.
A woman will then rise haughtily and announce, why, some days, she doesn't even think about sex once.
And then of course the debate begins to rage like a forest fire.
The root of the matter, and again I am trying not to use words with sexual innuendo for fear of losing intellectual respect.
And of course that is hard, with the most recent World Health Organisation figures revealing that 23% of all words in the English language have sexual innuendo for men (0.4% for women).
What IS thinking about sex?
I personally have no idea.
Like former US President Bill Clinton, I don't even know what sex IS.
You will remember his claim that what he and Monica Lewinsky got up to in the Oval Office was not sex.
I guess he called it heavy petting.
But heavy petting clearly involves thinking about sex.
What colossal degree of insensitivity could be brought to the table by a man so being indulged who was thinking about his share portfolio, or whether the weather would hold for golf later that day?
Sadly, Bill Clinton, who loves a round of golf and who seemingly oozes Vesuvian charisma whenever he walks into a room, was nevertheless very wrong-headed on this one.
I can imagine some pretty damn testing scenarios to try to define thinking about sex, just in everyday life.
I can imagine, for example, during one of my daily pop-ins to an op shop, finding Angelina Jolie, in disguise of course, standing by the summer dresses rack holding up a very reasonably priced item, shafts of sunlight dancing through its wafer-thin fabric, asking me if I thought it suited her, whether perhaps I could accompany her to that changing room over in the corner behind the stack of Readers Digest Condensed Books to aid in the decision-making process.
What thought would think its way across my mind at this point?
Would it be to perhaps suggest she was in the wrong place to find adoptable children?
Would I be plucking up the courage to compliment her performance in Pushing Tin, the most startling Film Featuring Woman I have ever seen?
No, I would not be of that mind, my mind would be racing like a racing car, and I would only have 1499 thoughts left for that day.
There is so much research done on this urban myth, from Kinsey, in 1948, on.
The most ridiculous number I found was, for men, every seven seconds.
Dreams are obviously part of that apocryphal statistic.
There is a thing called White Bear Syndrome which says if you ask a child to put their hand in the air and not put it down until they have finished thinking about a white bear, most will have their hands in the air forever thinking white bears.
Men and women asked how often they thought about sex with a clicker to press nearby, would presumably come up with a similarly disbelievable result.
I do not think in 2016 you can hold a legitimate dinner party without addressing this crucial aspect of human behaviour, which is, let's be brutally clear, even more important than the imminent flooding of South Dunedin.
Please bear all this in mind before speaking up at Christmas dinners this year.
● Roy Colbert is a Dunedin writer.
