I am old enough (52) to think that the past couple of generations are not being taught proper manners and respect for others. Not to say that elders never annoy me, but usually it is a younger type.
"In my day"

there was a time and a place. We curse amongst ourselves and friends and family to be sure, but never ever within earshot of a child, or an older person, or frankly- someone we did not know.
I was taught to hold a door open for whomever was behind me too. I had to (and still do) hold doors open for my Mother regardless of the situation. She would stand quietly outside a door forever if one of us forgot to open it for her. It just was not done.
I still M'am and Sir all of my clients whether they are older or younger than me.
If I am supposed to be somewhere at noon I am there at five til.
And so on...
Not to sound like too much of an old codger, but I believe that many people focus too much on the reactions their words and actions will receive- everybody wants to be a comedian. You try to get the first snark in, the first rude analogy, the first laugh.
And don't get me started on cellphones. On of the ladies I work with talks on a cellphone nearly all day long, and in Portugese to bat. To my way of being raised that is rude on two counts. You excuse yourself to take a phone call, not subject everyone in the room to your chatter. I can kinda sorta excuse the non-English aspect, but to hear it day after day all day makes me feel as if I am working in Brazil. I'm working on accepting it.
Life has become a free for all. No one remembers to "walk a mile in my shoes", or "never judge a book by it's cover". It's a shame. Life is so much more pleasant when folks just try and be aware of what type of effect their behavior has on other people. That does not mean not being true to yourself, or not being honest in your emotions. It just means being considerate.