In an alternate universe where the Star Wars series wasn’t the catalyst for the explosion of nerd culture, George Lucas was contracted to have a low-budget sequel prepared to follow A New Hope, in case its returns were disappointing. He wrote a story about two of the original film’s heroes, Luke and Leia, getting stranded on a swamp planet. When Episode IV worked like gangbusters, he took the best pieces of this story and fit them in The Empire Strikes Back.
But Lucas wasn’t finished with his original story. Rather than have it be forgotten to time, he tapped science fiction author Alan Dean Foster to write the book that would kick off the Star Wars Expanded Universe, Splinter of the Mind’s Eye. The first Star Wars book is fascinating, in that it gives the world a glimpse into what could have been. In the original Star Wars novel, characters don’t act like themselves, tech that nerds have spent decades lusting over acts differently than it’s supposed to, and there are entirely new spellings for famous characters. Was Splinter of the Mind's Eye an actual fever dream? It's certainly not the Star Wars you're familiar with.
In 2015, Lucasfilm took all of their Star Wars Expanded Universe stories and placed them under the banner of Star Wars Legends, as a way to both preserve the canon of the films, and provide an alternate universe that fans both new and old could enjoy. The Star Wars books and Star Wars comics that make up the Legends series might not be the Star Wars you remember; sometimes they’re spectacular pieces of science fiction that involve your favorite characters, and sometimes they’re utterly bananas stories like Splinter of the Mind’s Eye.
Luke has always been kind of a wiener. And when you compare him to literally every other main character in the Star Wars universe, you see how big of a baby he is. But, in Splinter of the Mind's Eye, he spends most of the book either acting like a bratty 12-year-old or bossing everyone around. In no particular order, he slaps Leia across the face, makes constant backhanded remarks about a variety of characters, complains about water a lot, and talks about his life on a desert planet like it was some kind of wealthy boy's boarding school. To clarify: he is the hero of this book.
This is probably the strangest thing in the book, or at least the hardest to reconcile with the rest of the Star Wars canon. By now, you know that Luke and Leia are brother and sister, and while it's not revealed to the audience until Return of the Jedi, George Lucas opens the book with a forward where he brags about having a nine film saga planned out prior to the filming of A New Hope.
Upon reading Splinter of the Mind's Eye, the reader immediately realizes that Lucas is full of it, or by "planned out" he meant that he figured there were probably nine stories to tell and he would get to them eventually. The fact that Lucas had oversight of Splinter and didn't tell the author Luke and Leia couldn't be a thing because of they were brother and sister, means Lucas was mostly making things up as he went along.
Just to really push this point home, there are multiple instances throughout the book where Luke and Leia have inner monologues about all their downstairs feels for each other. But there's really no better way to sell how Luke feels about Leia than this passage from the 2015 Legends paperback edition: "Even when bothered, to [Luke] that voice was as naturally sweet and pleasing as sugar-laden fruit." Gross, bro.
Before you guys draw conclusions about how big of a square Alan Dean Foster is, he wants the readers to know that he's a groovy '70s guy who has totally smoked a joint once or twice in his life. Pages 52 and 53 contain this very telling scenario that was definitely not written by a narc. See, upon entering a bar on Mimban, Luke can't breathe in the air as it's thick with a curious odor. "The princess chuckled, 'Too much for you fighter pilot?' ... 'Basically, I'm a country boy, Leia. I haven't had too much exposure to sophisticated entertainments.' She sniffed the air appraisingly. 'I wouldn't call these scents sophisticated.'" This Alan Dean Foster guy is a regular Cheech and/or Chong.
To add to the confusion as to where Alan Dean Foster stands on the issue of you being super cool if you use mind-altering substances, there's an alien race on Mimban referred to as "the Greenies" who debase themselves for a simple taste of alcohol. Halla, the witch that guides Luke through most of the book, mentions that Greenies do whatever they're told for a drink. The scene the audience is treated to features a Greenie licking mud off of a miner's boot, so they're kind of the Charles Bukowski of alien races.