The internet and social media has fed the tribal tendency. But for most grown-ups, discussing the minutia of a hobby over the ether is unlikely to translate into tribal fraternalism in real life. I would never dream of crossing the street, as it were, to accost a pipe smoker I didn't know on the assumption that he would relish taking time out of his day to discuss burley blends and retrohaling with a stranger.
We do that on here because that is the purpose of a special-interest forum and participation is voluntary and engagement a deliberate act of choice. But then, I suspect most of us on here are of an age that predates social media and we learnt our social skills face to face, so we understand such boundaries implicitly. I wonder whether the same will ever be true again for future generations.
Maybe there's a cultural element here as well. The majority of members on this forum are Americans. I'm from the UK where we're possible somewhat more socially conservative. Our equivalent of fist-pumping a stranger and addressing him as "brother" because he happens to be a fellow pipe smoker, or motorcyclist, or wears the same sort of hat, is to proffer a reserved nod from about ten yards away and then move on.
And talking of motorcyclists, I am also one of this breed and one of my motorcycles (I have three) happens to be a Harley Davidson. I often stop off at bike meets for a cup of tea and a natter and to wander round looking at the bikes. When I'm on my KTM or my Ducati, I'm just a normal member of the human race and the usual civilities apply. When I'm on the Harley, non-Harley riders seem to avoid me, perhaps on the assumption that I won't want to talk to them, while fellow Harleyists seem to think that by purchasing this make of motorcycle I've become a member of some sort of secret society that warrants a rather over-familiar semi-hug and a silly handshake by way of acknowledgement. I wish they'd just stick to the nod and the regulation chat about whether it might rain this afternoon.