In this clip of the movie Moana, Maui says:
I know, not every day you get a chance to meet your hero.
The line starts at 49 seconds into the video.
I think the meaning of the boldfaced clause is as follows:
You don't get a chance to meet your hero every day.
Then, shouldn't there be a subject-auxiliary inversion as follows?
Not every day do you get a chance to meet your hero.
And I thought that the subject-auxiliary inversion was mandatory when a negative adverbial phrase (e.g., not every day) was fronted.
So, how come Maui didn't say "do" right after "not every day"?
Also, if this was in writing, would the original sentence be grammatical?
EDIT
In response to the suggestion that the question might be a duplicate, I wonder if all of the following auxiliary-inversions are natural and idiomatic in spoken English:
Never you get a chance to meet your hero.
Not only you get a chance to meet your hero, but you get a chance to hang out with them.
Rarely you get a chance to meet your hero.
Seldom in your life you get a chance to meet your hero.
Only if you're a true dedicated fan you get a chance to meet your hero.
Not too many times you get a chance to meet your hero.