I think I learned this lesson on my second day in game. I was in Cherno and was incredibly excited to have found a super rare and amazing Lee Ein! I was wondering around near the Warehouse near the docks and train tracks when I notice two guys running from a group of zombies, I didn't shoot because they were unarmed, and I was still naive. One was named Brother Bear, the other was Penis (Should have taken that name into consideration...) They are grateful that I didn't shoot them and even more so that I took care of their zombie friends. They ask me to follow them, and so I do and we meet Brother Bear's Friend, Father Bear, who just so happens to have an AKM... Well we went about looting and having fun in Cherno for a good hour or so, until our friend Penis get's his hands on a Makarov. We'd been friendly so far so I caught us off guard when we found ourselves murdered at the hands of our friend Penis! Father Bear killed him though... Was my first time interacting with other people in Day Z, the first of many! Most of which resulted in gunfire... but I think this story shares the same morale value as the first one!