One of the great ironies of human existence is that, as we increase our knowledge of the world around us, we’re also discovering that — uh — we don’t actually know dick — about tons of stuff.  I’m not talking about quarks or gene sequencing or quantum physics or all that other scientific hocus pocus.  That’s for people who are interested such things, and we generally have to take their word for what works and how.  No, I’m talking about everyday occurrences.  Stuff that just happens and nobody really knows why.  Of course, there are theories, but — so far — we’re still guessing.  Personally, I think Mother Nature is just giving her smarty-pants children a smack to remind us to stay humble.  Anyway, here are three examples, and if you have another theory, feel free.  I’m always open to suggestions.

Yawning  — We yawn when we’re tired.  We yawn when we’re bored.  We yawn when other people yawn.  We yawn when we’re about to commit a felony.  (Didn’t know that, did you?)  Even animals yawn.  But nobody knows why.

Dreaming — Everybody dreams and everybody from Sigmund Freud to the guy who cuts your hair has a theory about why we spend our sleeping hours creating fiction.  Unfortunately, these are all just theories, and at last look, even Stephen Hawking doesn’t have a clue why we dream.

But, my favourite is:

Gravity — Everybody knows what gravity is until you ask somebody to explain it.  Try that, and you’re going to get a bunch of mumbo jumbo that ends up with Isaac Newton.  The problem is Newton never explained gravity; he just said it existed.  Here’s the deal.  The sun has enough gravity to keep the Earth from wandering off into space like a lost puppy.  The Earth has enough gravity to keep the Moon spinning around us.  And the Moon has enough gravity to affect the tides back here on Earth.  However, go 200 kilometres straight up from where you’re sitting, and there is no gravity — none!  Where did it go?  That’s a good question that I don’t think even Einstein ever attempted to answer.