I'd say handling people is the most important thing you can do as a coach. I've found every time I've gotten into trouble with a player, it's because I wasn't talking to him enough.
After landing his invasion forces on the shores of some country, the sixteenth-century Spanish conquistador Hernan Cortes would immediately burn his own boats. He was sending his army a message: "We can't turn back. Either we succeed here or we die here." Excuses were not an option.
You always have to prepare for the obstacles that are going to come. Consequently, when they do come, it doesn't affect you mentally near as much as when you're unprepared for them.