In the second aliyah of Parshas Vayigash, Yosef cries when he reveals himself to his brothers. This is not the first time that we encounter the tears of Yosef. After all of the years of struggle, there can finally be tears of joy. Yosef recognizes that all of the challenges of the past were only to bring him to this point. Only Yosef is able to clearly see the purpose and the joy from all of the struggles, unlike Yaakov and the rest of his brothers.