One of our regulars, Lincoln, came to the store the other day with his dog, Zeno. This isn’t unusual; Lincoln and Zeno often end up at the bookstore after their jaunts through the woods and lakeside trails in our town. What was unusual was that Lincoln wasn’t looking for a book. “I’m reading five at the moment,” he said, “and while I’m tempted, I can’t add another to the mix.”
This led to a lively storewide discussion of reading habits: who reads one book at a time, and who likes to have several books going at once. (The store was split about 50/50, though that may be an atypical sampling.)
Each camp was firm in its preferences; the one-at-a-timers couldn’t fathom wanting to juggle several storylines simultaneously, while the several-at-once-ers enjoyed the opportunity to engage with the different sides of their reading selves as the mood struck.
The strength of the readers’ feelings reminded me of conversations about monogamy versus polyamory (having more than one romantic connection at a time*). (*This is obviously a simplistic reduction of polyamory. I’m using it as a metaphor.) As with mono/poly preferences, readers seem innately and strongly drawn toward one style of book love over the other. 
I was a several-at-once-er as a kid and read as the mood struck me. On any given day, I might start with a deep dive into a fantasy world, and then—after an interruption of some kind—switch to silly poetry, or a mystery, or something spooky. “I contain multitudes!” my young reading soul would shout, and I rarely had fewer than three books going at a time.
These days, I’m still relatively book poly. Right now, I’m listening to Elizabeth Acevedo’s warm and memorable realistic YA novel, With the Fire on High (beautifully read by the author) and reading Sarah Blake’s The Guest Book and Rebecca Solnit’s Whose Story Is This? I’m also reading Ijeoma Oluo’s So You Want to Talk About Race for a discussion group in town. These books are all so different from one another that they meet different needs and moods, and fit into different contexts of my days. 
But sometimes I’ll start three or four books, looking to be swept up by just the right literary suitor, and when the right one comes along, I’ll abandon the others and just focus on the sparkly new love. On those occasions, I suppose I’m neither book mono nor book poly; I’m just a heartless spinebreaker. 
When it comes to your reading habits, are you book mono, book poly, or something else altogether?