Well, it’s the first working day of the new year. Perhaps, then, it’s time to investigate the year that’s just passed by way of Amazon’s recently released, insensibly titled “Customer Favorites: 2015’s Top-Selling New Releases” list. Why does the fact that something sold well mean it’s a customer favorite? Can’t you buy something on a whim and hate it? But ignoring, for the moment, Amazon’s insidious conflation of consumerism and taste, there is still much to be made of its list.

Let’s begin with The Girl on the Train, the year’s best-selling book. It’s a novel that reflects its reader’s insecurities back at them in a secure way, one that scratches the readerly itch for an unreliable narrator. Yet, at every turn, these readers (or “customers”) rather prove the need not for unreliability but for reliable unreliability. Or, as Janet Maslin put it, “The Girl on the Train has more fun with unreliable narration than any chiller since Gone Girl.” Given that Gone Girl was published last year, that’s a lot like saying “2015 is the most year since 2014.”

Anyway, to drive the point home, the press recently released an image of Emily Blunt as Rachel from the forthcoming film version of The Girl on the Train. The takeaway from every news item about the image was, “Does she look like the character in your imagination? Did it satisfy the mental image that you’ve come to rely upon?” And if there is any question whether the damaged, unreliable, post-traumatic mental state has become a consumerist fact, just look at the blurbs for Jessica Knoll’s Luckiest Girl Alive, the year’s 17th best-selling book. It would appear that Knoll’s protagonist is the luckiest girl since the gone one.

Fans of Gone Girl and The Girl on the Train will thrill at “the perfect page-turner to start your summer” (People, Book of the Week): Luckiest Girl Alive — described by Reese Witherspoon as “one of those reads you just can’t put down!”

“Loved Gone Girl? We promise [Luckiest Girl Alive is] just as addictive.” — Good Housekeeping

“With the cunning and verve of Gillian Flynn but an intensity all its own, Luckiest Girl Alive is a debut you won’t want to miss.” —Megan Abbott, author of Dare Me and The Fever

“Luckiest Girl Alive is Gone Girl meets Cosmo meets Sex and the City. . . . Knoll hits it out of the park.” —Fort Worth Star-Telegram

Another lie put crankily to bed by this year’s best-selling fictions is the idea that readers value originality. Take, if you want, E.L. James’ Grey, a retelling of the original 50 Shades story from the perspective of Christian Grey. As reader Mikayla points out in her Amazon review (and defense) of the year’s second best selling book, “This is a retelling of the original story but from Christian’s POV — therefore how can the author make it be different or original.” Can’t argue with Mikayla.

It hardly matters whether Harper Lee was sound-of-mind when she signed off on the year’s third best-seller, her sophomore novel Go Set a Watchman; any which way you slice it, the entire thing was an orchestrated get-rich-quick con on the part of publishers. Still, this proved what big publishing probably already suspected: when it comes to pillaging the living or the dead, you can get away with anything as far as readers are concerned. This is true even despite the loudish wailing of journalists.

Nora Roberts, Michael Connelly, James Patterson, John Grisham, and Lee Child are on the list as usual.

A man is injured in a sports accident and is suddenly unable to remember anything — this is not the plot of David Baldacci’s Memory Man, the year’s fifth best-selling book. No, the plot of this book, which proves that a man’s perfect memory is almost as bankable as a woman’s imperfect one, is the opposite: a man is injured and he can’t forget anything. It’s sort of the most predictable superhero story in an age when the internet actively erases our own working memories.

Two of the year’s best-selling books are works of “adult relaxation” — coloring books for adults. To be sure, the presence of Adult Coloring Book: Stress Relieving Patterns and Enchanted Forest: An Inky Quest & Coloring Book on this list presages a likely trend, one that my have us talking about connect-the-dots books for adults at this time next year. But why is everyone so grumpy about adult coloring books? Does it really make sense for a culture that privileges the “art” of someone like Wes Anderson, a man who also directs cartoon movies, to chide adults for wanting to color ornate images? This is also a culture where 70% of YA books are purchased by and for adults. The real question: why not combine the two? Who will be the first to make a killing by placing adult coloring illustrations inside YA novels? We’ll probably find out next year.