The saying, "walk a mile in someone's shoes before judging him" is because we often do not understand what we have not experienced. That goes both ways. It's not just me not understanding him, it's him not understanding me. And us spending time together provides an opportunity to understand each other. So when I want to get something done, that person will better understand where I am coming from because we've talked so much. It goes the other way too. When he requests a change from me, I'm very willing to accommodate.
The depth of a relationship may not be based on the sheer number of hours spent together, but it does take hours to develop a deep relationship. Life is about our relationships.