I belong to a generation that rebelled against what was quaintly called middle class morality, the echo of Victorian prudery that banned the discussion of many aspects of reality. Though we didn’t know it, our attitude was nothing new. The fin de siecle avant garde made a career out of “Épater la bourgeoisie,” that is, shocking the dainty sensibilities of the privileged class.

It wasn’t all bad. Protesting the misguided Vietnam War, racial discrimination and second-class citizenship for women still seem like reasonable causes to have embraced. And freeing up what could be said, written and performed wasn’t all bad either. Though “Shameless” isn’t to everyone’s taste, a diet restricted to “My Three Sons” was a bit bland.

Thanks to the mixed blessing of a zillion channels and cyber amusement at our finger tips, we can all now inhabit our own media bubble so long as we stay at home, in our wired car or armored by headphones. We all risk turning into solitary boys and girls in our own personal bubbles.

Except when we occasionally venture out to the larger, noisy, justling, diverse world, as we do at this time of year. There we encounter Sartre’s definition of hell — other people. Then we perhaps begin to miss an artifact of the vanished world of our youth that we threw overboard.

Yes, I’m speaking of that fuddy duddy concept we will call manners, for the want of a better word. The middle class morality we sneered at was erected on standards of behavior which apparently are no longer taught or expected. If you didn’t conform to a few such rules, your school teacher was quite likely to have a humiliating talk with your parents, and the pain would soon trickle down to you.

What set me off on this musing was a few recent trips, one on an airplane and a couple to the multiplex. Flying in coach is already a descent to an anarchic world that bears more resemblance to those trains in India crammed full to overflowing where excess passengers cling to the exterior. Only they seem to be more polite about the experience.

Crammed for hours into a space too small for your person in a metal tube 35,000 feet in the air, you are likely to be assaulted by strangers elbows, noises, or seats reclined so aggressively as to fracture your kneecaps and push your femur out of it’s hip socket.

On our most recent flight there was the usual delay, and we arrived at our destination late and likely to miss our connection. We were not alone, and the flight attendants made a feeble attempt to call for politeness. Those without connections were asked to remain seated and allow those forced to run from the plane, dragging their luggage, to sprint down the concourse before the next door was slammed in their faces.

You know exactly what happened. Every single soul on the plane went deaf and ignored this plea, stood up immediately, clotted up the aisle, and caused the half of the plane with connections to miss their flights and many of them to wind up stranded overnight. Politeness is clearly for sissies in a world whose only morality is eat or be eaten. Survival of the meanest and maximum selfishness rules.

And then there’s the horror of two hours at the movies, an experience that used to be a communal joy, a crowd of people in the dark sharing an experience. No more. Patrons now seem to believe they can behave at the theater the same way they do in their living room in front of the big screen TV.

Often the folks in the next seat or in the row fore or aft begin talking loudly when they arrive and never stop until the final credits roll. They blather during the coming attractions and from scene one to the final fade. On the few occasions they turn their attention to the events on the screen, for which they paid a sizable admission fee, they talk back to the actors much as they presumably pipe up to encourage or diss “Hannity” or “Real Housewives” at home.

Of course not all moviegoers suffer from logorrhea. Many are silent for two hours, but they spend their time ruining the film for others by stupidly gazing into their smart phones. Rather than being able to lose themselves in another reality, the magical dreams on the big screen, they are fixated on their little screen. These devices flare like fireflies from the rows ahead as OCD sufferers feel the need to check their cell phone every five minutes.

To escape one such offender, I recently left my seat and climbed up to the less populated back row only to find a guy four seats down had put his phone on the seat next to him. Every minute or two it would emit a burst of light, and gazing down from my aerie I could see every phone in the theater blink its morse messages which all added up my abandoning all hope for a couple hours of uninterrupted pleasure in the dark.

I am not alone. You hear stories all the time of even worse atrocities at big ticket performances on Broadway, at the Opera, ballet or symphony. Some solitary chimp will feel no shame about taking a flash picture in the middle of a performance or interrupting a soliloquy with the personal ringtone he has declined to silence. These piggish acts break the fourth wall and the audience’s heart. On a few occasions, an outraged actor has stopped in mid-sentence and told the barbarian to get out or the play would not go on. I’m on his side. You may have bought a ticket, but so did everyone else. You aren’t at home anymore, so don’t act like it.

I recently attended a string quartet recital only to have the mood broken when some egomaniac decided the music was so wonderful it had to be shared with family and friends who weren’t in the room. So, she held her phone aloft and video-recorded the Bach while blocking the view of everyone behind her.

Prudery and a finicky insistence on form over substance, a hypocritical unwillingness to speak the names of common human activities was one thing, but a complete absence of manners, consideration and respect for one’s fellow humans is the road to a coarse, vulgar, unpleasant world where every man puts his personal whims ahead of those of everyone else. Soon the only recourse will be to barricade oneself in a home as if in a medieval keep. Little will be gained, and much will be lost if we refuse to live by a few simple rules of decorum.