We all meet different kinds of people as we live our lives. Some remain acquaintances, some become friends, some annoy you, some really push your buttons, and some hurt you. Sometimes - a lot of the time, even - those who hurt you are your friends. So how are you supposed to avoid that pain?
Well, you don't.
That pain will come no matter who you are, no matter how many friends or enemies you have, no matter how much you hide away from the world. That pain is simply a fact of our fallen world. We hurt those we care about. Relationships change, for better or for worse.
The point isn't to avoid as much pain as possible, but to let God work through that pain. He doesn't directly cause us to suffer, but He allows things to happen that humble us or turn us away from a certain path to bring us closer to him.
You might have heard that said before. You might remember something you went through, or you might be struggling right now, and you think, "How does that possibly make me want to draw closer to God? He's letting this happen to me!"
I admit, in the midst of things, your vision is fogged with pain. When you break a bone or get hit in the face with a soccer ball (maybe even twice in one night...not that I'm speaking from experience or anything), it hurts. It hurts so much that all you can feel is the pain. Your vision blurs, and you go into survival mode, doing whatever it takes to make the pain go away.
We do the same with our emotional injuries. We curl up inside of ourselves and grit our teeth, waiting for it to fade. Sometimes it does. Sometimes it doesn't. Either way, our first thought usually isn't, "This is so great! God is really teaching me something here! Thanks, God!" In fact, getting to the place where we're willing to open up to what God has to say about things is a long and convoluted journey. People get lost along the way and give up. They get stuck in the wilderness. Who can blame them? It's hard to keep beating a way back to the path.
The simplest solution to dealing with someone hurting you is often to shut them out; to pile the blame on their heads, run away, curse their name, question why you ever bothered with them. It might even completely be their fault, but that does nothing. The pain is still there, and every time you think of them, it pricks you to remind you it's still there. It's not healing. It might scab, but every tiny movement rips it open again (yeah, gross.)
However that situation might end up - whether you eventually work it out, never speak again, apologize, or agree to disagree - there is always good to be found in it. That's what's amazing about having a God who cares about us personally.
I get it, the pain is still there. Sometimes it still aches. But once you're out of the rapids (or preferably when you're still in them), look back and see how God used that to your advantage. It's there, I promise. It might not have been your preferred way of learning that lesson, but it's certainly the most effective one.
To regret knowing someone, even when they've caused you hardship, is to regret the work of God in your life.