Anywhere you go, you are going to have to deal with a lot of different personalities. Not just nursing. Now I have been a nurse for 5 short years but I have learnt a few things. Some nurses are not very nice to their opposites on the unit, they feel the need to nit pick about everything, and some other nurses are very nice. It's the same everywhere. The original poster was correct, you cannot control anything others do, but you can control your response and your behaviour. I agree that the UM influences the atmosphere on the unit, that is very true.
Finally most of us work long hours in a stressful environment, if we all checked our attitudes at the door and stayed professional and courteous to each other, the job will go a lot smoother. Let's cut each other a little slack. We are nurses, we rule the world