Pay attention to this and internalize it; this is incredibly important. I have been involved in plenty of scenario-based training, and force-on-force training that involved roleplaying, and I quite often acted as the so-called "bad guy". Several people, mostly veteran LEOs, have made note of the fact that I think and act, and react, much more like a career criminal, than like the common "good guy" does. They will not do what you would; they are not you. They do not want what you want; they are not you. They do not fear what you fear; they are not you.