Ever since his brothers' appearance, Joseph must have been struggling to keep a cap on his emotions. One could think that Joseph knew what Jesus would say when Peter asked how many times we should forgive those who hurt us. When we acknowledge how many times God has forgiven us, we are free to forgive others. The three elements needed for forgiveness to be genuine appear in this story. There is the acknowledgement of the sin in the brothers' lament that after 22 years they are still being punished for selling Joseph into slavery.
Forgiveness is never cheap grace that overlooks sin.
Often we need to inform another of hurt that has come to us. We can be unaware of hurts we cause others. There is no forgiveness without naming the sin. Everyone knows the beast is there, but no one says anything. And more than that, no one does anything to get rid of it.