Plot amnesia is a popular trope because it's such a useful way to advance a narrative. In the Bourne films, or Captain Marvel, or any number of pop culture stories, the hero doesn't remember their backstory. They have to discover who they are and what they're supposed to be doing, and at the same time the reader or viewer get to discover the same things. Rather than a boring info dump at the beginning of the movie or book, you learn vital details as the protagonist does, uncovering their past as you get deeper into the plot. You and the hero are in the same position; you've forgotten how empowered you are, and the film (or book, or whatever) is how you remember. It's a gimmick, but it's an elegant gimmick.
G. Willow Wilson and Cary Nord's Wonder Woman Vol. 1: The Just War makes extensive use of plot amnesia. The populations of entire planes of reality conveniently forget their past, to ramp up suspense and mystery. And yet, the use of plot amnesia here is not elegant. It's a clumsy mess—which, inadvertently, serves as a metaphor for the clumsy mess which is mainstream comics storytelling.
The Just War begins with Ares, Greek god of war and longtime Wonder Woman villain, imprisoned on Paradise Island, or Themyscira. He convinces a fellow prisoner to kill him. This causes some sort of rip in the fabric of reality; he next appears in some European country, where he starts a civil war. Wonder Woman (aka Diana Prince) rushes off to stop him, more or less successfully. She gradually discovers that all of the gods and inhabitants of Olympus have appeared on earth, and that maybe Themyscira, her homeland has been destroyed. Also, the daughter of one of Diana's old enemies, Veronica Cale, was on Themyscira, and her disappearance reignites the old conflict. Also also, Aphrodite finds Diana's warrior boyfriend Steve Trevor who was kidnapped for a while, so Aphrodite and Wonder Woman team up. Oh, and there are a trio of displaced Olympians—a Pegasus, a minotaur, a faun—who provide comic relief.
As that description indicates, The Just War is not tightly plotted. Though the title says "Volume 1", it is, like most mainstream stories, plopped in the middle of DC's ongoing continuity, and the story makes precious little effort to catch you up to speed. When Ares' killer (a never very clearly identified blue-skinned woman) asks him, "What have I done?" she could be speaking for all of us, or at least for me.
The problem isn't that the narrative is difficult to follow: Wonder Woman fights various bad guys, then rushes off to try to save other people, as you'd expect. Nor are the themes especially deep. Diana tries to figure out when war is justified, and then the problem is solved for her when the two sides in the ongoing civil war improbably decide to sign a peace treaty. She and Steve Trevor muse on how war used to be great way back when. This is irritating and dumb, but not especially hard to follow.
But while the lack of articulated backstory isn't confusing in the usual sense, it does rob the story of emotional weight. Even the character development for Diana herself feels slighted. Wilson's characterization of Kamala Khan in Ms. Marvel was refreshingly specific and original, from her glee at joining the Avengers to her nausea at using violence to knock out a villain. But Diana's worries and motivations seem rote and indistinct. She wants to save people because that's what Wonder Woman does, rather than because Wilson has made her a person who wants to save people. And as for the rest of the cast: Who is Veronica Cale, anyway? Why is she angry at Diana? For that matter, who is Diana's mother? What is their relationship like? Why are we supposed to care if she has disappeared? How am I supposed to get invested in this story when no work is ever done to get me invested?
Of course, I'm supposed to be invested already because I'm supposed to be a fan. I'm supposed to know who Hippolyta is from comics past. I'm supposed to grin at seeing Etta Candy show up, because I'm supposed to have a backstory with Etta Candy.
And I do, kind of—I wrote a book about the original Wonder Woman comics, and I like past versions of Hippolyta and Etta a good deal. But despite that, I don't really know these versions of those characters very well. Etta the tough bad ass fighter pilot is a bit like Etta the unapologetically fat sorority sister who likes to spank the bad guys, but they're obviously not the same person. And as for Hippolyta, she's barely in the comic. There's not much there to grab onto. Rather than developing actual characters or relationships, Wilson and Nord just gesture vaguely towards a yesterday of half remembered meaning—an assumed collective experience obscured by unacknowledged aphasia.
It's in this context that Wilson's bizarre use of plot amnesia makes a kind of willfully counter-intuitive sense. All the people of Olympus—Ares, Aphrodite, the faun and the minotaur, and others—don't' remember how they got to earth. Rather than just having the main character have plot amnesia, Wilson erases the memories of an entire divine realm full of beings, including around half the players in her comic.
Having all these people and creatures forget the major plot point of the comic is a logistical decision. If you want Wonder Woman to figure out what happened to Olympus, you can't very well just have Aphrodite explain to her what happened to Olympus. Where's the fun in that?
But beyond the needs of the plot, the wholesale forgetting also mirrors the odd gaps in narrative, affect, and construction which afflict mainstream comics. Superheroes are a massive, global obsession; Wonder Woman is one of DC comics most successful film characters. But the Wonder Woman in The Just War isn't that Wonder Woman. This Wonder Woman is pitched to a small number of enthusiasts. It's less about telling a story and more about moving familiar pieces through familiar scenarios for the small number of people who have shown by their dedication that they want to see the "superheroes should be registered" plot again. And then see it again.
Plot amnesia is supposed to help regulate and rationalize the gaps in reader knowledge. It's a clever shorthand method for making sure that audience and protagonist share a common frame of reference. Mainstream comics, though, has largely abandoned the effort to speak to new readers; it exists in a world that even the vast majority of Wonder Woman fans (those who follow Gal Gadot) don't understand. I felt for the Olympians, dumped in a world they never made for elliptical reasons; forced to wander through pointless adventures interacting with people they don't know and don't particularly want to know. I sympathize so fully, in fact, I would like to rescue others from their fate. Which is why I encourage you, dear reader, to forget about buying this book.