The Gemara says that there were two ‘nekamos’ (revenges) one was good and one bad. Rashi explains the bad nekama was Hashem’s vengeance on the nations for rejecting the Torah, and the good was Hashem’s freeing their mammon to Yisroel on account of their refusal to receive the Torah. If it is viewed from the nations’ perspective then certainly both can be considered bad revenges, alternately if we are viewing from Yisroel’s viewpoint they are both considered good, why then do we say that one is bad and one good?
We learn that a bracha is said upon seeing a multitude (600,000) since it contains the full spectrum of minds which equal that number, and is reflected by their dissimilarities in facial features as well. Since there certainly exist more than 6000,000 people in the world, this apparently denotes that there are duplicates as well, if so why don’t two people ever look alike?