It is the pinnochio syndrome, if you lie your nose gets bigger and you can smell a liar (which of course is you) until you assume the whole country is composed of liars and criminals.
Everyone assumes everyone else is just like them, if they cheat they justify it because they assume everyone cheats, if they lie everyone lies, if they steal everyone steals.
This is why some Christians cannot believer there are actually people so evil they drink children's blood, they don't do that so they assume no one does. Even though the Bible tells them the whole world lies in the evil one.