When An Immovable Object Like You Can Not Be Challenged, It Is Difficult For Anyone To Get Upset Because There Is No Emotional Payoff
People operate on an assumption about you. They assume you can be rattled, that you will swallow their pitch, that you can be nudged into leaving them be or doing whatever it is they want. Have you ever just watched someone, read the feeling they were broadcasting and the thing they were angling for, and then quietly decided you would not take the bait? Sometimes you can predict exactly what a person is about to do just from how they carry themselves, the way you can read a dark, rolling storm cloud. I remember a woman at the farm store who was dressed to make an impression, and the impression she wanted was that she belonged to some higher class and would therefore get her way. You could tell she was about to get angry. So I turned my cart down a different aisle and got out of range. She was looking to stage a scene and win by upsetting somebody, probably a clerk, and if not a clerk then a shopper like me. She had that self-righteous, stately air, primed to go off the moment she found someone who would feel responsible for her mood and hand her the satisfaction of being right.
Here is the small revelation: I do not have to volunteer as the victim in someone else's production. I can stay calm, I can walk away, and by doing that I refuse to give such a person the payoff they came for. There is a version of this at home too. I can feel it coming when my husband is getting ready to find fault with me, usually over something I actually did, like eating the last piece of cake (the smallest piece, naturally), or losing the car keys, or setting them down somewhere I can no longer locate. The simplest move is to own it plainly. I tell him, flat and without drama, that yes, I did the thing. Once I have admitted it in that matter of fact way, there is no opening for the upset he was hoping to build. I confess before he even gets to the accusation, and I do it without feeling guilty or getting mad at him for catching me.
Meditation helps build this muscle. In meditation you let yourself relax and allow thoughts to drift past without chasing them. The same habit works here. You can train yourself to decline the guilt and the emotional spiral, to not let a thought circle until it starts to hurt. Chewing on a situation usually gets you nowhere, especially when you already know what you should have done or what you intend to do differently later. Manipulators are skilled at forecasting how people will act and feel, and that forecast is how they get what they want. For instance, they can almost always rely on a person doing the polite thing.
Cultivate a blank face. It is a real defense against these people. So is the line, "Oh, were you talking to me?" It tends to throw them off, because what they are counting on is your attention, or at least somebody's attention, or (heaven help everyone) the whole room's attention. There is no telling what they are itching to unload, or why they are so sure a willing target will be standing there.
Be like a duck and let the water roll off your back. Stay undisturbed. You can often postpone a thing until later, when you have time to think and no one is pressing you for an answer on the spot. Manipulators are banking on you being flustered, too scrambled to produce a decent response. My late half sister-in-law tried exactly this once, in front of a crowd, when she asked me in a cutting voice, "Who cut your hair?" I happened to have a comeback ready: "Who asked you?" She had a reputation for ambushing people this way and getting away with it, and she counted on her target not having time to think of anything to say. Another option would have been to turn to someone else in the crowd and ask what they thought of her remark, or of how I looked. As unkind as she could be, and everyone knew it, most people there would probably have come up with something on my side.
You are not obligated to be anyone's mark. You just have to plan ahead, manage your own feelings, and refuse the role. Sometimes the answer is to leave while telling yourself, or them, "I don't have time for this." If you feel you need an excuse, say you are busy, or that you are tired and have had enough for one day. And if it comes to it, you can be as blunt as they have been rude. You can name what they are doing, say they are trying to manipulate you, tell them to get out of your face, that you are done putting up with it for the day.
The same technique works on your own thoughts and feelings. Tell yourself, "I don't want to feel that way anymore," or "I don't need to feel guilty about that, I have done that enough already," or "I am sorry for what I did and I have made my amends, spiritual or practical," or "Yes, I need to deal with that, but now is not the time," or "I have thought about this enough today, and obsessing over it is not moving my life forward."
Notice that manipulators never put themselves through this. They collect their reward and spend no time feeling bad about it. So do not dwell on having been manipulated, except long enough to recognize what was done to you and to limit the damage where you can, quickly if the clock matters, like stopping a check before it clears. That is the practical thing any person in that spot would do. Then file the whole episode under experience and move on.
Some people cause harm sideways, without grasping that they are hurting others and themselves in the process. It can end in the quiet collapse of a relationship, with the blame landing on the other party, while the person who is angry never sees their own hand in the breakdown. A lot of it seems to depend on mind reading. Say I do a favor for someone who needs help, and they have no idea it was an imposition on me, and then they ask me to do it again, still not realizing it is a burden. I privately feel they should not have asked twice, but of course they could not know that, because I never said it.
The whole pattern runs on treating mind reading like a sport. I will do something generous for you, but you are supposed to just know never to ask again, because it cost me something. Tangled, isn't it. The only real counter is to say something to the person after the fact, if you get another chance to talk, and point out that they should have said "No" the first time, or said, "I can do this once, but don't count on me for it next time." Though that road can open up a long parade of shoulds about who ought to be helping you instead, and on and on it goes.