I make the same two resolutions every year, even though I know I cannot keep them. The thing is to try.
The first is never to be annoyed by the bad manners of others. It’s okay to deplore bad manners or even to respond with righteous anger, if that’s warranted, just not when you’re annoyed.
If someone cuts you off in traffic and you chase after them thinking “I’ll teach you!” and cut them off in return, there is very little likelihood that you will improve their manners.
Sometimes a well-timed comment can educate an ill-mannered person, but you can’t think clearly enough to make one if you’re annoyed.
So I focus on not being annoyed. I take a walk or a bike ride. I had a boss once who drove me crazy, but I found that after a 20-mile bike ride he went from being annoying to being funny, hilarious in fact.
Then I’d go back to work and if he started in on me I would look at him and he could see that it was all I could do to keep from laughing out loud and he’d back off.
My second resolution is never to announce you know the answer to someone else’s problems. If someone is talking about a problem that they find intractable, it’s incredibly boorish and conceited to say, “Your problem is simple. I saw the solution right away.” If you want to be helpful, there are much better ways.