When dialogue is way too ahead of its time

About 10 years ago I was watching a new "major motion picture" that featured well-known actors and was set overseas in the 1950s.

At one point, one of the characters said, "Sounds like a plan."

Huh?

Now, mind you, it wasn't as jarring as it could have been if the guy had whipped out a cell phone, called his girlfriend and asked her to TiVo something for him.

And I suspect that the actor may have been ad-libbing.

But still.

Yesterday I was reading a short story set during the late 1930s in Hollywood and featuring some celebrities of the time along with other characters.

As an old-movie buff I know a lot about this era.

At one point, a character said, "Who's the Marx Brother wannabe?"

Wannabe?

A word whose first recorded use, according to Merriam-Webster, was in 1981?

Now it is true that the story was narrated by an anonymous character who wasn't there, who says this was the way he (or she, for all I know) heard it.

So maybe the author could argue that the narrator has a faulty memory or a tin ear.

But still.

I'm not trying to nitpick. But anachronisms like these "take me out" of the story, make me aware that I'm reading something, or watching a movie or TV show, instead of experiencing it.

And that's not where I wannabe.