Long 'Dunkirk' teaser is making people think they're in the wrong movie theater

"Am I in the wrong theater?" anxiety.

We've all had it.

But this -- this is a whole 'nother level: Warner Bros. has been playing an extended scene from Dunkirk in movie theaters during the traditional previews slot, and the long, non-traditional "trailer" has been causing confusion.

Understandably so.

The 7-minute reel -- a complete scene from the film, not the usual cut-together sizzle -- first played at CinemaCon in April, and turned out to be the perfect selling point for Christopher Nolan's film about the pivotal Allied military evacuation in 1940.

While Warners has since cut multiple trailers for TV and online, they've not released the long scene anywhere ... except in movie theaters. With little explanation or fanfare.

Several individuals, including no less than three Mashable employees (and at least two acquaintances from outside work), described roughly the same sequence at recent screenings:

• After a string of regular preview trailers, a message appears that the "feature presentation" is about to begin

• Warner Bros. and Syncopy (Nolan's production house) title cards flash

• Then begins the scene from Dunkirk -- Tom Hardy in a Spitfire, dogfighting with German planes; soldiers desperately trying to carry a fallen comrade on a stretcher to a departing boat; civilians preparing their boats to go aid the evacuation

• As the scene drags into its latter minutes, people start to look around, get up to go check the marquees and ask ushers whether they're in the right place

Some people told me they (or their companions) thought it was the beginning of Wonder Woman -- also a Warner Bros. movie -- because that was indeed what they had come to see ... and it's war-themed, with a plane crashing into the water, so why wouldn't there be dogfighting near the beach?

Let's be clear: No one's been hurt, angered or even much inconvenienced by the Great Confusion of Dunkirk, and Warner Bros. had no comment on the response.

Just be warned: When Dunkirk comes out July 21, if you go and it opens an a bunch of Amazons training to fight, you are definitely in the wrong movie theater.