1. They help us settle with parts of ourselves we’ve avoided facing. Coming into conflict with people often forces us to draw on resources we’ve forgotten, and perhaps even refused to acknowledge, that we have. For instance, I remember a few opposing lawyers whom I couldn’t stand dealing with. I felt they were rude and overly aggressive, but my deeper problem with them was how often I had to say “no” when I interacted with them.

2. They remind us how much we’ve grown over time. Recalling a difficult interaction we had with someone a long time ago can remind us how far our development has come today. For example, I used to harbor a grudge against a woman who ended her intimate relationship with me many years ago. I believed she did it in a demeaning way and I felt angry at her.

Today, however, when I think about the conversation where she broke up with me, I actually feel peaceful and empowered. I see how personally I took the things she said, and how painfully afraid I was of living without her, and I know I wouldn’t react in those ways to the breakup if it happened today. I’m a stronger and more self-sufficient person now, and although I enjoy intimate relationships I don’t need them to feel like a complete human being.

The memory of my last conversation with her serves as a progress report showing how much I’ve matured since then. I’m grateful to her because, if she’d never been in my life, I wouldn’t have such a clear indicator today of how far I’ve come.

3. They help us admire ourselves for overcoming obstacles. Difficult people help improve our ability to handle challenges, and when we deal with those challenges effectively we gain self-respect. I had a professor in college, for instance, who was known to be particularly harsh in his grading. I probably spent more nights studying into the early morning for his tests than I did for the other courses I took combined. I defied my own expectations by acing the class.

Today, I fondly look back on this man’s course, and my dealings with him, as examples of how tough and persistent I can be. I’m grateful to him for helping me respect and admire myself.

4. They help us make important life decisions. People who, in our view, “give us a hard time” often help motivate us to change our circumstances in positive and fulfilling ways. For instance, I know a number of people who changed their careers, at least in part, because they got tired of dealing with what they saw as their overly demanding and critical superiors. They might not have the career satisfaction they have today if their old bosses hadn’t been as tough to deal with.

5. They help us see our opportunities to grow. Uncomfortable interactions with people can make us aware of places where we don’t fully love or accept ourselves, and where we could stand to develop more appreciation and compassion for who we are. One example stands out from a job I had when I was just out of college. A woman in the office, who seemed consistently stressed and angry, used to call me “what’s-your-name” when demanding I do things for her. I’d feel very distressed when she called me that, and I’d experience a burning sensation in my chest and upper back.

A few years later, as I reflected on this memory, it occurred to me that I got so upset when she talked to me that way because I had such an aching need to be acknowledged by others. I needed people to constantly tell me I was important and praise my accomplishments, and thus when this woman treated me like I was nobody I felt terribly anxious.

When I had this realization, I started taking up practices to dissolve this need—to develop a sense of wholeness even without constant acknowledgment from others. I wouldn’t have the peace I have today if this woman—whose name I, ironically, don’t remember—hadn’t been there to show me where I didn’t fully accept myself and needed others’ approval to feel complete. And I can genuinely say I’m thankful she came into my life.