It appears that Joseph reconciles with the brothers after he reveals his identity to them. He calms them down and says, "while you may have thought [selling me as a slave] was a bad thing, God considered it a good thing. It enabled the saving of an entire people [from starvation]." They then proceed to live their lives apparently at peace. But all is not well.
After their patriarch, Jacob, dies, the brothers are seized by the fear that Joseph will now take revenge upon them. They invent a message from their father: "Please forgive the sins of your brothers, for they have done evil to you." When Joseph hears this, he cries. Why, now, years after they supposedly reconciled, are the brothers in a panic that Joseph will pay them back? What was left undone?
There is an amazing story told about the great Rabbi Moshe Feinstein. After a dispute between two people was adjudicated by him, Rabbi Moshe instructed the parties to forgive each other. One did so easily. The other hesitated. Rabbi Moshe pressed him. The fellow said, "Not to worry, everything is okay." This was not good enough for Rabbi Feinstein. "You must say explicitly that you forgive him," insisted the Rabbi. The man gave in.
After the litigants left, a student asked Rabbi Moshe why he was so insistent. The Rabbi answered, "On Yom Kippur, we read the prayer about the 10 martyrs, the 10 rabbis killed by Rome. The prayer says they were killed as a punishment for the sin of the brothers when they sold Joseph. Wasn't that resolved at the time? The answer is, Joseph never said to the brothers that he forgives them. He said that it was for the best, that God had a plan, but he never said, 'I forgive you.'"
In other words, there was no complete reconciliation. The brothers felt this, and years later they still had a sense of guilt and fear regarding Joseph. How did this happen? Wasn't Joseph extremely magnanimous with them? He seemed to imply that they shouldn't feel any guilt whatsoever! "God considered a good thing," Joseph reassured them.
That is exactly where Joseph erred. His mistake was in absolving them from sin. If he absolves them from sin, then they didn't do anything wrong. How can they ever apologize? The brothers never do apologize. Joseph had prevented it. The closest they get is the invented message, put in the mouth of their deceased father, begging Joseph to forgive them. When they deliver this message to Joseph, they fall on their faces and proclaim, "We will be your slaves." But they, themselves, never say they are sorry. And Joseph never demanded of them. And so, they swept it under the rug where it continued to fester throughout their lives, and throughout Jewish history at different times.
Why did Joseph and the brothers fail to deal with the elephant in the room? Why did Joseph short-circuit his brothers' need to apologize? While that's a question for psychologists, I will hazard a suggestion. Sometimes people are uncomfortable being human. Being human means that you have feelings and that you are fallible. Very often, the people who appear toughest are the most sensitive. That toughness is an overcompensation for vulnerability. Joseph cries a lot in this whole episode, and those tears are his humanity seeking to express itself. Each time he suppresses it and acts as if he is above all this, his vulnerability chokes him up.
There is an additional aspect. There is no conflict between individuals that is not two-sided. Joseph also needed to apologize for the way he treated the brothers in his youth. His dreams, his privileged status, and his being a tattletale to his father contributed to the brothers' hatred. True, what they did to him was far worse, but he had what to say "sorry" for as well.
But if he absolves them from any guilt, he also absolves himself. Thus, Joseph's approach of, "Let's leave the past alone and just get on with our lives," is extremely unhealthy. We must own and embrace our own humanity. I once asked my teacher, Rabbi Aaron Soloveichik, if one is allowed to tell one's spouse how another person has hurt them. Would that be considered "Lashon Hara," or, evil speech? Rabbi Soloveitchik answered, "of course he can tell. If he can't tell his wife, it will eat him up from inside. Who else can he tell?"
The blockage to reconciliation is when we try to be above ourselves, negating our own humanity and feelings. We need to be truthful about what is in our hearts. We need to think about those with whom we have uncomfortable feelings, and we need to embrace them, too. That means being honest, sharing our feelings, and deciding together if we really want to have a future relationship. I can promise that reconciling like this is far sweeter than any revenge could ever be.