How did Yosef succeed in interpreting Pharaoh's dreams? What is the key to their interpretation? By noticing the discrepancies between Pharaoh's original dreams and the versions he recounts to Yosef, we understand the way in which Yosef utilizes these differences to prove his great wisdom to Pharaoh. We also notice that Pharaoh's dreams resulted in a transformative process for Yosef by shedding light on his own dreams. 

Courtesy of the Virtual Beit Midrash, Yeshivat Har Etzion