The first big disappointment in Joseph's life came when he was 17 years old. We read about this in Genesis 37. Joseph's brothers sold him as a slave to some bedouin traders who were on their way to Egypt. We read that Jacob, Joseph's father, had played favorites with his sons. Jacob should have known that this display of favoritism might cause friction in the family.
Parents run the same risk today when they play favorites with their children.
We also learn that Joseph apparently assumed a superior attitude towards his brothers which further aroused their hatred and jealousy. Now it was true that God was behind these dreams and they would all eventually come true. However, at this point maybe Joseph should have kept these dreams to himself. But let's not cut Joseph down without recognizing that we are guilty of similar failings. The most amazing and wonderful lesson for us in this part of the Joseph narrative is that God takes not only our disappointments but even our failings and works them into His overall good purposes for us and others.