Know what you can change.
Know what you cannot.
You really cannot change another person, be it their thoughts, actions, words, deeds, or driving skills (unless they are your own children, and even then . . .)
What you CAN change is yourself: How you perceive others, how you react to their reactions, how you treat them; how you present yourself to the world. In your car.
I used to revel in the fact that I could hurl, at what I considered to be stupid drivers, every epithet known to humankind while safely behind the wheel of my car; windows rolled up. I felt smug that I could let fly with all manner of foul language and no one would be the wiser.
No one but myself. And my heart rate. And my blood pressure. Eventually I would be enraged at not only every driver on the road, but simply enraged. And then others would know.
This does not make for peace and contentment, people.
Not being able to keep stupid drivers off the road is not something I'm likely to change.
My attitudes/actions? Now those I can deal with:
Quit yelling.
If others absolutely HAVE to go first, let them.
Give stupid drivers plenty of space - in which to be stupid and not affect you or your car.
Be kind, show some sympathy: That other person may have just received their driver's license; may be in unfamiliar territory; may have never driven in a round-about before; may not know the rules of the road as well as you, but who does?
Quit calling stupid drivers stupid. It doesn't help.
Leave the house, work, wherever, in plenty of time to get where you want to go.
Aaahhh. Life just got a teeny bit more peaceful.