Toward the end of Parashat Vayeishev, Yosef is imprisoned along with two of Par'oh's chief servants. Starting in Gen. 40:6, the Torah tells us that he notices that they look sad, asks why, and proceeds to interpret their dreams for them, which ultimately leads to his interpreting Par'oh's dreams, becoming viceroy of Egypt, and reuniting his family.
I seem to recall some commentator suggesting that it's significant that all of those good results started with Yosef's simply being sensitive enough to his fellow prisoners that he noticed their sadness and asked them about it, but I haven't yet found who it is. (I've scanned the standard Mikra-ot Gedolot commentaries as well as R' Hirsch so far.)
Have you seen this idea written down anywhere?