You know what I mean? A good thing happens, and you think, Uh-oh, this can't really be for me. Wrong name, wrong info, someone mixed up the orders and I was supposed to get the plate of Sorry, not Congrats.
I think most people I know have felt it in some way or another. When I arrived at grad school, certain that my admission was some kind of accounting error that would now be corrected ("oops, that was supposed to be for Chelsea Johnson,") several of my classmates confessed the same lingering dread that the acceptance letter had been a mistake and that they too would be imminently, apologetically sent home.
Impostor syndrome can be totally debilitating and destructive, of course, but it can also be understandably common in certain contexts (see above). And in its milder form, says the New York Times, it can function as a social strategy, a way of self-deprecating to set low expectations that you can easily meet and exceed. ("Feel Like A Fraud? At Times, Maybe You Should.") Also, it affects women more, particularly high-achieving women.
The feeling tends to manifest itself in one of three ways, as per this older but more detailed Times article:
Workaholics, who attribute their achievements to their compulsive efforts. They are so fearful of failing that they approach every task as though it were crucial.Because they never slack off, they never learn whether or not their own innate ability would carry them through, and so perpetuate the sense that without efforts greater than everyone else, they would be exposed as failures.
Magical thinkers, who prepare for tasks under the burden of intensive visions of failure. Because their preparation typically ends in success, they see their worrying as always paired with success and an essential ingredient. Thus thoughts about failure become superstituously liked with efforts toward achievement.
Charmers, who flatter or flirt with their superiors, while doubting their basic ablity to succeed without these wiles. When success does come, they attribute it to their looks or social skills, rather than to their own competence.
Anyone else out there know what I'm talking about? For me, it dissipates once I get into the thing and get my footing, but anytime I'm offered a new good thing it rears up again--I will be unmasked--and here come the anxiety dreams every night.
Another useful thing I learned from this is that both "impostor" and "imposter" are acceptable spellings.