Of course, no one has mentioned the most famous and inspiring story of them all.
When the Yom Kippur War broke out, every reserve in the country was called up. R’ Aharon knew that he couldn’t help in the war (being a solider takes training and such) so he went to the reserves office to find out whatever he could do to help the country. He was told that there was an extreme shortage of milkmen. Too many reservists were milkmen and there was a serious concern that many people would not be able to receive their milk. So R’ Aharon volunteered and became a milkman for the duration of the war.
R’ Gustman ZT”L had just made Aliyah. On a particular day, B’siyata Dishmaya he was on his doorstep talking over a difficult Sugya with a Talmid. (Stories diverge here as to exactly what the Sugya was and why R’ Gustman was having trouble with it, but they all agreed he had some Kashyas he couldn’t answer.) R’ Aharon walked up and delivered the milk. Overhearing the conversation, he answered R’ Gustman’s Kashyas and explained the Sugya clearly according to R’ Gustman’s Mehalach. And then R’ Aharon proceeded to give an entirely different Mehalach that was better anyway.
After R’ Aharon left, R’ Gustman exclaimed to his Talmid, “Baruch Hashem! In this country even the milkmen are Bekiyim in Kol Hatorah Kullah!”