I've GMed a few Roleplays while here on RPG and I have yet to have a fully successful one and that's mostly at my own fault. I'm very laid-back as a GM and therefore have never had any arguments with any of my players. On the other hand, however, I'm very lenient and tend to let people "do what they want" so long as they aren't disrupting the main flow of the Roleplay. Which. . can let you quickly become a doormat to your players and their ideas. In a way, it's not very different from how I might act as a player. 

However, I also think that there is also a "GM you" and a "player you". 

As a player, you have a duty to fulfill both your character and other players. As a GM, you have a duty to fulfill your character, other players, plot and many other aspects. As a GM, I feel that I am much more organized than as a player. Same goes with leadership, but that's pretty much a given. Anyone can be a GM, but not everyone can be a good one. I'm still learning to become a good one, so I believe that's why I haven't had many personal conflicts with "GM me" and "player me" unlike some of the other stories here. 

A good GM has likely run into "GM them" and "player them". After all, people need to adapt to different situations.