Some actors, and especially the younger actors, they come into the job with a lot of attention on how they behave and everything when they're not working. Sometimes that can be unfortunate because the work call is pretty intense and the preparation for it. If your focus is there, then the actual doing of the job will be fun and enjoyable. But if you're so involved in trying to be interesting and a character and everything when you're not working, it can get in the way and people get goofed up.