Rashi to 45:4 says that when Yosef told his brothers to approach him, it was to show them his circumcision (presumably to prove he was Jewish). But how would that prove anything? All of Egypt had been ...
While Yosef recognized his brothers, they did not recognize him. I heard a Rosh Yeshiva suggest that Binyamin, who wasn't so absorbed in the soap opera, was able to recognize Yosef, but played ...