I found this article and thought it was very well written and articulated, with great examples of setting boundaries and healthy/unhealthy responses to a boundary. What is interesting to me about this perspective are the examples of healthy and unhealthy responses to someone setting a boundary, which is very telling of that person's health.

How He or She Responds to a Boundary Is Telling | Psychology Today

I am working on boundary setting and am getting far better at it.

A life lesson for me has been to not allow others to disrespect, disregard, take advantage, step on and abuse me. I have experienced all of the above, and I am still learning how to sidestep these types of people, address the disrespect, or walk away as necessary. I am getting far better at both addressing it and at walking away. I am proud of how far I've come, but I still have a ways to go.

Someone told me (a spiritual medium) that my most recent ex was here to teach me how to recognize treachery. He was very manipulative, and a pathological liar. Thankfully, I caught on before it was too late and I gave him the boot.

I still can get triggered by someone being disrespectful, but I am getting better at processing it, then dismissing it and letting it go without it ruining my day.

What I've also determined is that only miserable people spread misery and negativity. Happy, balanced and mentally healthy people do not do such things.

So whenever I come across someone now who is clearly just a miserable person spreading their negative energy and anger around, I realize that it's their own misery talking, I can feel some amount of compassion towards them even if they're being rude towards me, and I can dismiss them much more easily.

I am working on just being happy with who I am and where I am in life. And I pretty much am a very happy person, in many ways. So that makes me feel good.

I do have a ways to go still so that I don't get triggered by nasty people I encounter in life, but I am getting better at it and I'm proud of that.