In one dazzling moment, the brothers’ world was turned upside down. ... They might have taken comfort in self-pity and self-righteousness had they been standing before any other accuser, but the man who stood before them was Yosef, the one person who knew their darkest secret, the person who had been their victim, the brother they had put out of their minds for so many years....
They never saw it coming: The dramatic, unexpected end to the saga in which they were embroiled was the last thing the brothers anticipated - and that was precisely the problem. The scrutiny to which they had been subjected seemed unwarranted. Why, of all the visitors who came to Egypt to purchase food, had they been singled out? Why the interest in their family, their father, their brother Binyamin?
When they attempt to return the money that had mysteriously turned up in their bags, the brothers’ misinterpretation of the events that had transpired in Egypt becomes clear: They convince themselves that everything that had happened was part of a plot to rob them of their possessions and their freedom.
When the men [realized that] they were being brought to Yosef's palace, they were terrified. They said, 'We are being brought here because of the money that was put back in our packs the last time. We are being framed and will be convicted, our donkeys will be confiscated, and we might be taken as slaves.' (Bereishit 43:18)
Had they thought things through more calmly and rationally, they might have asked themselves why the second-most powerful man in Egypt would need some paltry excuse to seize their meager possessions; moreover, the Egyptian ruler’s modus operandi - placing his own money in their bags - seems strange and counter-intuitive: Had the Egyptian wanted to keep their donkeys, he could have left all of the brothers in prison, rather than freeing them after three days, and their donkeys and very lives would have been his.
Apparently, the human mind has a powerful capacity to rationalize, justify and fabricate alternative explanations to the obvious when the simple truth is too difficult to face. In flagrant disregard for Occam’s Razor, the brothers built intricate and improbable hypotheses to explain their predicament. Had they been able or willing to open their eyes, they would have saved themselves so much confusion, fear and angst. Their adversary was not a stranger; they had known him their entire lives, but were unable or unwilling to recognize him. The obvious solution eluded them, because in their minds it was impossible in so many ways. This person could not possibly be Yosef: Yosef was a dreamer, with no grasp of reality. Yosef was probably not even alive: As a slave, Yosef must have annoyed his master to the point that he did what the brothers themselves could not. On the other hand, who other than Yosef would have cared about their youngest brother and their father? Who else had any reason to throw them in prison? Who else cared enough to carry on this protracted game of wits, to maintain contact only to continue to threaten and abuse them?
The brothers never dreamed that they would bow to Yosef; ironically, when they finally did bow before him, the brothers were unaware that Yosef’s dreams had come to fruition: They did not know that it was Yosef to whom they bowed. They bowed to the man who controlled all the food in Egypt; in a very real sense, they had not bowed to Yosef, but to a strange Egyptian potentate. They never dreamed that this was their own brother.
The Midrash offers a more detailed account of the moments in which Yosef finally revealed himself to his brothers: At first, Yosef told them that their “missing” brother, the brother they had claimed was dead, was in fact very much alive. The brothers were stunned, incredulous. Yosef then assured them that this long-lost brother was in the palace; in fact, “he told them, ‘I will call him and he will appear before your eyes.’ He called out, ‘Yosef son of Yaakov, come to me! Yosef son of Yaakov, show yourself!’ The brothers scanned every corner of the room, searching for Yosef, until Yosef finally declared, ‘I am Yosef’ - and the brothers (almost) died. (Bereishit Rabbah 93:9)
Even when they are told that Yosef is in the room, they look everywhere - except at the man who stands before them.
Sometimes, jealousy and hatred can be so strong that we underestimate the person who is the object of our hatred. By belittling their worth, we justify our own bad behavior. Because the brothers hated Yosef, they could not see the truth - even as it stared directly at them. When they were finally forced to recognize Yosef, they were dumbfounded, shocked almost to death. As if struck by lightning or confronted by a ghost, that moment of enlightenment forced them to recognize their many crimes.
They had hated their brother for no reason. Yosef had not been suffering from delusions of grandeur; he was, and always had been, capable of greatness. They suspected him of vanity and a false sense of superiority, but it was they who suffered from myopathy: They could not, or would not, see what was, and always had been, right in front of them. In the end, they had bowed to him, just as he had dreamed they would. They relied on him for sustenance, as his dream foretold. They understood, too, that if revenge was on his mind, he was certainly in a position to do anything he wished to them, and not merely take their few donkeys.
In one dazzling moment, the brothers’ world was turned upside down. They were not victims, as they had imagined, of this man’s abuse; they themselves were the abusers. They might tell their story, and perhaps even garner sympathy from anyone and everyone else – but there was one person in the world who was not fooled. They might have taken comfort in self-pity and self-righteousness had they been standing before any other accuser, but the man who stood before them was Yosef, the one person who knew their darkest secret, the person who had been their victim, the brother they had put out of their minds for so many years. Yehudah’s impassioned speech, so full of righteous indignation, suddenly seemed hollow, even laughable. Now, they were forced to remember: They had another brother, he was in the room, staring right at them, and he was everything they had tried to deny: Yosef was a visionary, a man of unparalleled talents and strengths, a man of the highest moral caliber. He had risen far above them in every way, but he was willing to go even further, to do the unimaginable: Yosef was willing to forgive them.
For a more in-depth analysis see: http://arikahn.blogspot.co.il/2015/12/audio-and-essays-parashat-vayigash.html
 Occam’s (or Ockham’s) Razor states that among competing hypotheses, the one with the fewest assumptions should be selected. In other words, the most straightforward explanation is usually correct.