A nod or a wink

If you've never noticed it, look out for it - it happens all the time. When motorcyclists ride past one another on opposite sides of the road, nine times out of ten, they'll give a little nod of acknowledgement. This behavior is not exclusive to bikers, oh no. drivers of certain models of - often classic - cars will do the same as will Eddie Stobart drivers and the like.
This little nod says a whole lot more than a simple hello. It signifies that you are part of a wider group; you're in the know; part of the scene.
But us cyclists tend not to do it - at least not as a rule anyway - there's no accepted acknowledgement of others culture in cycling is there.
Being a reasonably glass half full type guy, I'm often found saying 'how do' to passers by or offering thanks to people who shuffle their crazy hounds out of my way.

But many, many don't bother and I think it's to cycling's detriment.
Maybe we don't acknowledge other cyclists because if you did, then you'd do little else - a nod to each passing rider on the Fallowfiled Loop on a summer evening would end up looking more like a semi-permanent nervous tic.
But even when there are few riders around, some people just refuse to acknowledge their role as an ambassador of the cyclists union.
There's a guy who I ride past on a daily basis who I basically rub shoulders with in absolute silence.
I thought, incorrectly as it turned out, that saying 'alright mate' would make the whole process a bit less odd. He obviously thought I was some kind of simpering idiot on day release and didn't even acknowledge my existence.
Maybe he's just ignorant, but it's weird. 
So, I think it'd be a better world if we all said hello to each other. More often. When riding. As long as its not too often cos that would get too weird.
Or maybe I'm completely out of tune with public thinking on this one?