Suppose there are two people who we will call "A" and "B" for simplicity's sake. They live together with a brick wall around them for shelter and protection. One day they get into an argument that gets out of hand, and in the course of the dispute violence is done to the brick wall, and it falls down. They live for a while with the rubble around them, but then it becomes apparent that their hostile neighbors, cannibals, have discovered their vulnerability and are preparing to do something about it.
A approaches B and says that they should rebuild the wall together. B agrees but says that the broken wall was not his fault. A says that he is willing to repair his part of the wall, and B agrees to do his part. They both begin at the same spot to build a circular wall, the supposed plan being that they would meet again half way around the circle.
A begins to build. Ah, this feels good. He gets half way around the circle and looks up. B has assembled a few beginning blocks, but now considers his part finished. A has a problem. He could just say he did his part, but he can see the threat outside the wall growing. He could try and persuade B to do his part, but that might result in the half circle of wall getting broken down again. He decides to keep building.
A builds until he has come full circle. While he was building, B undid the little that he had done. Finally A puts the last brick in place. He approaches B and shakes his hand. B is satisfied because the wall is built again, and together they face the enemies with their wall of protection.
Sometimes life is like this. You meet people who are so willful and stubborn that they cannot give an inch. They will not admit wrongdoing. They are so blinded by your faults that they cannot see their own. These people don't compromise, and they don't become better people. If we can't escape them, we have to accept their brokenness. Sometimes this means we have to do more than our share. We have to repair not only what we have broken, but what they have broken too. It's not fair. But if we can do it and shake their hand without resentment, we have done all we can do. It is called forgiveness.
The best case scenario does not always happen. In fact, most of the time it doesn't. That's why walls get broken down in the first place. Someday B might just decide to build a roof over the wall to protect both of them against the elements and remind A every time it rains how much A owes him. And if A has truly forgiven B, he will simply say, "Thank you."