Toxic people rarely have any idea how toxic they are. In fact, they mostly wonder — with feelings of hurt and outrage — why so many people they’ve loved have been so “unfair” to them.

These people don’t necessarily appear to be monsters. You might like many of them when you first meet them. But if you allow them to stay in your life, they’re going to drag you down — and the start of a new year is a great time to resolve to cut their poisonous influence completely.

As with other toxins, some toxic people are more deadly and dangerous than others. Some are obviously toxic from the beginning. Others present themselves as self-sacrificing saints, so they appear to be good people. Yet others will make you so dependent on them that you dare not upset them.

Toxic people frequently claim to love you, but they’re confused. They have a desperate need to be loved and wanted — often hidden from everyone, including themselves — so what they call love is really need. Their version of love is making claims on your life, telling you what you owe them. In their own sick minds, you might as well be a part of their own bodies — because they see you as something they have every right to manipulate.

Toxic people rewrite the past and believe their own lies. It doesn’t matter how many people tell a toxic person what he’s doing to others — his friends or people in his family or people he works with — because he’s going to ignore those people’s testimony. Those people can’t possibly be right, in his own mind, because what they say conflicts with his own narrative. When people close to him say, “You’re hurting me,” he ignores them, because they can’t possibly be right. Why?

Toxic people don’t really know you, but they believe they do. They tend to have a static idea in their minds of what you should be — and that’s all you can be to them. If you tell them who you really are, they don’t listen if it conflicts with what they expect you are (or should be). That’s because their view of you is whatever you need to be to give them what they want. For them, no relationship is mutual or equal.

Toxic people need to win at every phase of a relationship, even when they appear to be giving. They know what makes them feel good, so they do those things to feed their own wounded egos. They want everything their way in a relationship — and they’re unwilling to let you go when you try to walk away from an unequal relationship that’s hurting you.

It rarely matters if you explain to toxic people what they’re doing to you or how the relationship can be repaired. They care only about hearing whatever bits and pieces will allow them to manipulate you — so they can get what they want.

Toxic people are manipulators. They don’t understand psychological boundaries — and don’t care if you try to impose them — because all they care about is manipulating you to get you to perform as they want you to.

Toxic people are wounded and hurting creatures, although they’re often blind to whatever made them that way. Often, in fact, the people who hurt them the most are the ones they claim the most love and devotion for.

Toxic people are often narcissists. Until I learned the psychological meaning of narcissism, I completely misunderstood what that was. It doesn’t mean anything like what we typically mean when we talk about the vain person checking himself out in mirrors. A real narcissist — in psychological terms — often looks nothing like what society means by the word.

I had to learn a lot of things about narcissism — and about various forms of relationship dysfunctionality — when I was going through therapy with an excellent psychologist about a decade ago. I had to face a lot of things I didn’t want to know. Worst, I had to see some of my own past actions in ways that horrified me. I learned that I had been toxic in certain relationships — not intentionally and not enough to have destroyed anyone — but enough that I had to apologize for some things I’d said and done.

Almost nobody recognizes himself when it comes to narcissism or other toxic behavior. If you explain the details of what’s been going on to a toxic person, that person will be able to grasp the intellectual issues — but almost certainly will not be able to see himself as having created a problem.

If you have been trained to accept being dominated by someone else — and if you’ve been taught to build your life around how to please someone else — you might have trouble understanding what’s happened to you. Even if you know you’re miserable with life, it’s almost certain that you’ll blame everyone except the people who trained you to be that way.

Ultimately, it’s not about blame. It’s about learning to live an emotionally healthy life. It’s about giving up the constant fear of displeasing someone. It’s about setting healthy boundaries. It’s about walking away from what others expect you to be and finding a way to become who you need to be.

Cutting those people out of your life doesn’t necessarily meant you hate them, although their vicious reactions when you try to assert your independence might eventually make you feel that way. It simply means you care enough about yourself not to let that person destroy you, whether intentionally or not.

If you see yourself in any of this — either as a victim or (far more unlikely) as a perpetrator of toxicity, please get help. It’s never too late. You might have destroyed the relationships you’ve had along the way, but that doesn’t mean it’s too late to understand what you’ve done and why.

If you’re a victim, walk away completely. There’s nothing wrong with giving that person (or those people) clear indications of why something has to change, but don’t expect anything to actually change.

A toxic person won’t hear you.

A toxic person won’t respect your boundaries.

A toxic person has no interest in what you say other than as a way to learn how to manipulate you further in order to get what he wants. So don’t be surprised if this person who claims to love you completely ignores your explanations about how you’ve been hurt.

If you care about your own mental health and happiness, set boundaries with toxic people. If they refuse to honor your boundaries, they’re telling you they don’t care about your needs or who you really are. It’s time to cut those people off completely.

There is nothing in this world more powerful and life-giving than an equal, respectful relationship of love and understanding between two people.

But there’s nothing more destructive than a toxic person who leaves a string of hurting people behind him or her — and that’s far more common than you realize.

Learn to spot the toxic people in your life — and then stop them before they can destroy you.

Note: If you’re interested in learning more about psychological narcissism, a simple book called “Why is it Always About You?” is a good place to start.