HaRav Avraham Yitzchak HaCohen Kook zts"lFirst Ashkenazi Chief Rabbi of Israel, revered and famed Torah sage, philosopher, writer, poet, iconic and beloved leader of religious Zionism and the return to Zion (1865-1935).
Joseph, the ambitious protagonist of the final four readings of Genesis, was the "master of dreams." In addition to his own two dreams of future greatness, Joseph was called upon to interpret four more dreams: the dreams of the royal baker and steward, and Pharaoh's double dream about the seven-year famine.
All six dreams bore prophetic messages. "A dream," the Sages taught, "is a sixtieth of prophecy" (Berachot 57b). And yet, Joseph's dreams contained inaccuracies. Joseph dreamt that the sun and moon would bow down to him - i.e., even his father and mother would acknowledge his greatness. But, as his father quickly pointed out, Joseph's mother had passed away long before!
Nevertheless, "Jacob waited to see the results" (Gen. 37:11). He knew that this impossibility did not invalidate the rest of the dream. As the Sages noted in Berachot 55a: "Even if most of a dream comes true, not all of it will come to pass."
Why do dreams include extraneous elements and inaccurate details?
Rav Kook explained that this is due to the very nature of dreams. All dreams originate from our imaginative and emotional faculties. As a result, they are subject to exaggeration and nonsensical elements. Even prophetic dreams may contain details that do not correspond to reality.
This is because the truth contained in a prophetic dream relates to the general reality of what should happen. It may be that due to circumstances, certain details in fact occurred differently. This does not mean that the dream is false. Rather, the dream's message relates to what potentially could or should have occurred.
Joseph dreamt of his parents bowing down before him. In reality, Joseph's mother had died many years before. Yet the fundamental message of the dream was true, for had Rachel still been alive, she too would have bowed down before her son, viceroy of Egypt.