The darker middle chapter of an expected trilogy was a crushing disappointment for many Star Wars fans. People had waited years for this sequel, and what did they get? Two main characters became uncomfortably connected. A whole middle-of-the-movie subplot went nowhere. And Luke Skywalker seemed irrevocably tainted after a surprise revelation.

We speak not of The Last Jedi, which — mild spoiler alert — has some fans upset in part over aspects of the above. Rather we speak of initial reaction to what is now widely recognized as the best and most artistically important Star Wars movie, The Empire Strikes Back.

On its release in 1980, the long-awaited Star Wars sequel actually received a mixed reception. Largely because it was so very different from its predecessor, it took audiences several viewings to figure out whether they actually liked it. Star Wars was a blast, but this one was a downer, man. They didn't even blow up a large evil spherical object at the end.

Like The Last Jedi, Empire took a number of what were seen as enormous storytelling risks at the time. Not least of which was making you wait years years to find out whether the shock revelation — "I am your father" — was for real or not, and whether Han Solo would be released from carbonite.

In a world where Star Wars was still considered a flash in the pan, this non-ending — in a kid's movie! — was seen as the height of arrogance.

In the immediate aftermath of its release, both top critics and fan publications alike were shaking their heads. "It ends on a bleak note that may leave certain younger members of the audience shaking their heads," complained the venerable fan 'zine Starburst. Said the even more venerable New York Times reviewer:

I'm not as bothered by the film's lack of resolution as I am about my suspicion that I really don't care ... It's a measure of my mixed feelings about The Empire Strikes Back that I'm not at all sure that I understand the plot.

The Washington Post critic slammed the movie as having "no plot structure, no character studies let alone character development, no emotional or philosophical point to make." Some of its special effects were already "space-movie clichés."

Even The Phantom Menace did better than Empire

And the less said about the oven-mitt alien in the asteroid — the movie's belly-of-the-beast subplot, a retread of Star Wars' superior trash compactor — the better.

Contemporary audiences, of course, loved it. Or did they? We don't have Twitter from the time, which perhaps is a small mercy, but some fans on Twitter remember their initial reactions were a lot different than the judgment handed down by history.

Certainly, once we enter the VHS era of Star Wars, when everyone's had a chance to watch each of the original trilogy a zillion times, Empire becomes widely known as the best.

But its greatness was not entirely recognized by theater audiences — at least not if we judge by the numbers. Return of the Jedi made more money than its predecessor, meaning Empire Strikes Back was for many years the least successful Star Wars movie at the box office.

Adjusted for inflation, even The Phantom Menace did better business than Empire — as did The Force Awakens.

Quick reminder that experimental, darker middle chapters don't generally do as well at the box office. pic.twitter.com/wNG87v2L2S — Chris Taylor (@FutureBoy) December 19, 2017

Another reason the movie irked fans: the love triangle was unexpectedly resolved.

Ah yes, the love triangle. Recall that no one, not even George Lucas, thought of Luke and Leia as brother and sister at this point (Lucas originally intended a sister for Luke who was stashed far away across the galaxy in relative safety). Remember that Luke and Han seemed to have equal claim on the Princess' heart.

So yes — uncomfortable as it is to consider, there were a large number of what today would be called Luke-Leia shippers, and they were at war with the Leia-Han shippers. Though Team Luke scored an early victory in the movie with a long kiss from Leia, she ended up telling Han she loved him in the carbon freezing chamber.

In doing so, she wiped out the fan theory of a sizable chunk of the audience. The whole Han-Leia thing also made the whole series uncomfortably romantic for those who weren't on board with the kind of movie that Lucas called "Gone With the Wind in space."

And Darth Vader claims to be Anakin Skywalker, Luke's dad? What's up with that? The very thought was inconceivable to large numbers of fans — not least of whom was James Earl Jones. When the actor voiced Vader's infamous "I am your father" line, his first thought was: "he's lying."

So as we watch the Star Wars fan base grapple with its feelings on The Last Jedi, remember the lesson from the greatest chapter in its pantheon.

If at first you don't quite get it and it makes you angry for some reason, rewatch. And rewatch again.