Overestimating the agency of everyone and everything
Role-playing instead of trying to achieve goals
Expecting too clean a distinction between protagonists and antagonists
Underestimating the number, and overestimating the cohesiveness, of protagonists
Overly anticipating unlikely but dramatic events
(Most of these are more accurately described as “errors almost everyone makes all the time” than “dangers of thinking you’re in a story”, but thinking of them that way seems pretty useful for identifying them.)
More:
Overestimating the agency of everyone and everything
Role-playing instead of trying to achieve goals
Expecting too clean a distinction between protagonists and antagonists
Underestimating the number, and overestimating the cohesiveness, of protagonists
Overly anticipating unlikely but dramatic events
(Most of these are more accurately described as “errors almost everyone makes all the time” than “dangers of thinking you’re in a story”, but thinking of them that way seems pretty useful for identifying them.)
Assuming that villains exist, rather than the horrifyingly deep and complex behaviour generated by perfectly normal blithering stupidity.
Edit: After reading this comment, I’ll amend that to “Assuming villainy is the usual explanation for apparent bad behaviour.”
This is so common as to be an adage: “Never attribute to malice that which is adequately explained by stupidity.” (http://en.wikipedia.org/wiki/Hanlon’s_razor)
So what is villainy, if it’s not that?
They mean well, rather than being out to deliberately fuck you up.