I learned in Montreal in 5753. I remember being impressed by how R' Volf would sometimes motion with his hands instead of talking. Once I asked him a question in a Maamar, and he merely turned the page and showed me that the Rebbe asks the question a little further on, without saying a word. I took this as care about not speaking extra words.
I once had a question regarding something I wanted to write to the Rebbe, and I asked R' Volf. He told me "Freg by Rabbi Gurary, er is der mashpia." This expressed his humility.
He once saw me eating while standing. He told me "men tor nisht essen shteyendikerheit. S'iz nisht oisgehalten, al pi shulchan aruch."
Another time, he saw me take a second piece of mezonos before shacharis. He said to me "Tzvei seudos?! Heint darf der davenen zein..." and he lifted up his hands in the air.
I had a chavrusa who decided to ask R' Volf whether time-travel was possible. Since he didn't speak Yiddish, he convinced me to ask. I asked "is it possible to go back in time?" R' Volf answered "yeh." My chavrusa called out "al pi kabbalah?" and R' Volf answered "nein, al pi nigleh." Later I figured he was referring to Teshuvah.
I remember how at his Tanya shiur he would require the bochurim to wear their hats because it is the Torah Shebiksav of Chassidus. At that time, we had a hookup from 770 for whenever the Rebbe would come out on the balcony. We would of course only be able to hear the singing. This happened once during a Tanya Shiur. R' Volf stopped teaching, and throughout the singing had his eyes tightly shut, and tapped his foot. Afterwards he said, "M'ret doch (in the perek he was then teaching) vegen avodah mitoch simchah!"
During the time I was there, he didn't farbreng, and I understand that this was so from Chof Zayin Adar until after Gimmel Tammuz.
