"Vayinashek l'kol echav va'yeivk aleihem v'acharei chein dibru echav ito." (45:15) This is the completion of the story arc, says the Sefas Emes, that began with, "v'lo yachlu dabro l'shalom." (37:4) The brothers could no longer communicate with Yosef back then, but now, "v'acharei chein dibru echav ito."
In the preceding pasuk the Torah tells is that Yosef cried on the shoulders of Binyamin and Binyamin cried on Yosef. Rashi explains that Yosef was crying for the loss of the beis hamikdash, which was built in Binyamin’s portion, while Binyamin was crying for the destruction of Shiloh, which was built in Yosef’s portion. I saw an interesting diyuk: each one cried for his brother's loss, but not for his own.
I would say that this is what makes Klal Yisrael great. A person can suffer loss him/herself, but be able to put that aside and focus on the suffering of a brother or sister or friend.
R’ Shaul Yisraeli (in Siach Shaul) suggests another lesson we learn from here: it is often easier to see the churban in someone else's backyard than to the churban in your own.
Finally, the Lubavitcher Rebbe makes the same diyuk and also tells us something powerful: the purpose of crying is to show empathy; crying, however, can't fix the problem. When the churban is in someone else's portion, then you need to cry with them and show your support and caring. When the churban is in your portion, then crying is not enough -- you have to go fix the problem!
We are coming up to 10 Teves, a day of ta'anis, a day to mourn for churban. But mourning, crying, fasting are not enough -- we need to fix the problem in Klal Yisrael that are keeping us in a state of churban.