It may seem like something not so important, but, seriously, it is. Being extremely rude can prevent you from forming the most meaningful of relationships, whether they be friendships to something more, those types of relationships are compromised because they may see that you in your rudeness is something that can't be accounted for, whether by excuse or seeing why. It's still inexcusable.
But why?
It's all really simple to understand, really!
1) your rudeness in all its forms look not just bad on you, but also on your friends as well, and this is a stain that your friends really don't want to be scared with.
2) your rudeness may provide a barrier between you and others.
3) people will feel that your rudeness will extend to them, being rude has been shown or known to produce people who will swear at people over the simplest thing, which will put people of you even more.
This is what I hope will provide you with some ideas on how how not to treat people in everyday life.
Do not argue that someone annoyed you, that's beside the point, seriously. This is about how you react to every day stimuli, seriously it is!
The point of maturity hits when you can specifically react in a pleasant manner with people no matter how you may feel at that time or moment.