Reb Shimon would say that he learned something very valuable from the shoemakers. A shoemaker gets a torn shoe and spends hours repairing the shoe, but when he's finished he feels such a satisfaction even though what already came out? a repaired shoe. So too a person in their Avodas Hashem shouldn't look at what came out of his Avodas Hashem, the fact that a person can serve Hashem and a person puts in their whole soul in serving Hashem, that in itself should bring such satisfaction.
Rabbi Yechiel Michel Feinstein was in Warsaw in 1936/7 and he heard that Rav Shimon Shkop was in hospital so he went to visit him. Reb Shimon told him, "If the doctors would treat every patient like we treat every student it would be much better." (If we would treat our children and students like Reb Shimon treated his Talmidim...)
Rabbi Shkop started putting on Tefillin of Rabbeinu Tam in his latter years. Rabbi Gustman told over that the Yeshiva was learning Maseches Gittin and when Reb Shimon was on Daf Beis Amud Beit (page 2) he was struck by a Tosfos and couldn't understand the words of Rabbeinu Tam. He spent a few weeks trying to understand the depth of the Tosfos and the words of Rabbeinu Tam. Finally he came out with an amazing explanation and Reb Shimon was very excited. He said, "when I go up to Olam Habba I hope I will merit to see Rabbeinu Tam saying a shiur." "However," he added, "I have a problem. I am worried Rabbeinu Tam will look at me and say 'who is this person? he never wore Tefillin,' (Karkafta delo monach Tefillin) because I only wore the Tefillin according to Rashi which Rabbeinu Tam holds isn't Kosher." So Reb Shimon started wearing Rabbeinu Tam Tefillin.
