Last week, lovers of 80s nostalgia were shocked when allegations of plagiarism appeared against ‘Stranger Things’ creators and producers the Duffer brothers. Charlie Kessler, creator of “Montauk,” a 2012 short film similar in tone and concept to “Stranger Things,” filed suit against the pair.

Kessler says after pitching an extended version of Montauk to the Duffer brothers in 2014, and subsequently hearing nothing back, he was shocked when “Stranger Things” debuted two years later, according to TMZ.

The controversy has fizzled some in the days since as the Duffers released emails from November 2010 — two whole years before “Montauk’s” premiere — that lay out what appears to be the basic outline of “Stranger Things.” But the episode, paired with a similar lawsuit against “Shape of Water” director Guillermo del Toro from February, provide some food for thought: when is an idea your idea?

Well, the law is pretty clear on this. Copyright infringement (which is what we’re talking about when we discuss issues of the ownership of ideas) is more straightforward than it might seem, and in this case the crux of the “Stranger Things” controversy is this: did the Duffer brothers take Kessler’s intellectual property and claim it as their own?

From what seems to be available of the case, including the most recent emails released by TMZ, the answer seems to be no (though we do not constitute a court of law, and the jury is literally still out on this one).

However, this whole debacle begs a deeper question: when, in the world of art, does inspiration become theft?

“Stranger Things” and “Shape of Water” are certainly not the first creative works to be labeled thieves (see: decades of controversy over “The Lion King’s” many similarities to the Japanese “Kimba the White Lion”), and they won’t be the last.

Art must build on itself. This isn’t to say that originality is dead, but most art — especially commercial art like TV or movies, produced solely to turn a profit — is inherently derivative for this reason.

As Disney CEO Michael Eisner once said: “We have no obligation to make history. We have no obligation to make art. We have no obligation to make a statement. To make money is our only objective.”

So it should come as no surprise that, if we assume the Duffer brothers didn’t have an original idea, that Kesslers didn’t really either. Montauk is driven by the so-called “Montauk Project,” a conspiracy theory-turned-book that detailed government experiments, aliens and time-travel that all culminated in the 1980s.

In all honesty, the topic is ripe for re-imagining, and it’s not hard to believe that two people (or in this case three) could come up with the same idea at roughly the same time. Add into this equation the fact that the last five years have seen American nostalgia for the 80s hit overdrive, and it’s surprising that there aren’t somehow more stories in a similar vein.

At the end of the day, Hawkins, Indiana, is derivative of so much that came before it that it’s difficult to say it’s particularly original in any sense of the word. From the heavy undertones of Stephen King in the setting, to simple tropes like “cop with a past” or “government conspiracy goes wrong,” “Stranger Things” is painfully, purposefully, not “new.”

So, as this controversy does (or does not) drag on, look behind the simple similarities between one piece of work and another. To say that two movies focus on a similar plot is to ignore why those plots are similar in the first place, as well as ignores the fact that the only reason this is coming up at all is money.

One party feels entitled to their own creativity, and therefore also to the fruits of that creativity. And that’s fine, and by all means should be encouraged. But when auteurs insist on their own originality, be they Kessler or the Duffer brothers, so too should they be honest with themselves and their audience.