Why did Yaakov learn at the yeshiva of Shem and Ever?

At the beginning of last weeks parsha (ויצא) Rashi comments that before going to Lavan Yaakov stopped and learned at the Yeshiva of Shem and Ever for 14 years. The obvious question is why? After all Yaakov was 63 when he left Beer Sheva and had learned with his father for his whole life, what did he expect to gain from Shem and Ever?

R' Yaakov Kamenetsky (and I remember R' Goldvicht saying the same idea) answers as follows. The Torah of Yitzchak was good for someone who was completely sheltered from the outside world. However, when Yaakov left his father's house to go to Lavan he needed the Torah of Shem and Ever. they had gone through the Dor Haflaga, they lived in the world. They taught Yaakov how to keep the Torah ieven in a place like Lavan's house. Yaakov needed their torah to be able to go to Lavan's house and leave saying I kept Taryag mitzvos.

Rashi comments about Yosef (בן זקונים) that Yaakov taught him all the Torah he learned from Shem and Ever. Why specifically the Torah from Shem and Ever? The answer is that yaakov knew that yosef would be in a similar situation, he would go into Galus and therefore Yosef needed this same Torah that Yaakov learned before he went to lavan.