When Rav Aharon was still in YU (before he moved to E”Y), he once visited Rav Soloveitchik zt”l’s apartment in the Morgenstern dormitory. It was late at night, around 12:00, when suddenly everyone in the dorm was woken and urgently sent out by security – there was a bomb scare. My rebbe was there, and everyone including Rav Aharon was waiting on the street. Suddenly, a “kol korei” went around: Rav Aharon was going to give a shiur. Everyone was woken up, kicked out of the dorm, worried about what would be, but Rav Aharon’s first priority was to pass the time properly with a shiur.
Once, there was a three-day Purim in Eretz Yisrael. This talmid would be spending shabbos with a chevra, and for some reason was convinced by someone to invite Rav Aharon and his family for shabbos lunch. Rav Aharon said he had to check with his wife. As it turned out, that week was not a good time to come because he had a lot of guests. However, he offered to come and schmooze on shabbos afternoon. In shocked awe, the talmid accepted. Rav Aharon came and answered the questions of the chevra, which had somehow expanded from four or five guys to about 15.