Characters that Live their own lives

Since I've gotten some great feedback on the last post, I'm making you read another:P

The other day, I was about halfway finished with a scene when I realized how differently the characters were behaving from how I originally intended. One was being terribly selfishly while another was surprisingly supportive. One worries me that I'm going to have to adjust her behavior a bit to make sure things don't seem out of place later on, however, it was pretty neat to see them take on a life of their own!