Ok, so the theory that Zachariah put forth was that Dean was a hunter in his core, that even given different memories and a different life, he was not truly happy without the Hunt. Now, by extension in this episode, that fact seems true for Sam as well. True, Sam had the benefit of the visions, but it was SAM who was all enthusiastic.
So, my thinky thoughts are...if Jess hadn't died, If Dean hadn't come to retrieve Sam from Stanford, if the YED crap had never sucked Sam back into the life, if Sam had indeed become a lawyer...would he have missed Hunting?
Anyway, that's all.