These discarding shits are all different, but my ex-snake in the grass was exactly as you described.
She never maintained any close friends. I think maybe 3 or 4 times over 12 years did we visit or accommodate a college or high school friend. Half those times were weddings, then we never saw them again and she never spoke of them. She was always just close to coworkers, and then when she'd switch jobs, she'd forget the old ones and her new coworkers were now her "friends". It's no wonder she cheated with a coworker (and carried on an inappropriate friendship with one 6 years prior, both older men of course). I've got close friends who I've known for two decades, people I'd go to bat for every time. She reaped the benefits of my social circle.
So yeah, her lack of attachment to people never bothered me but in retrospect, it's an alarming trait, plus it assures me that she'll never ever reach out to me again. Imagine spending 12 years with someone, they act like everything's fine up until the day you catch them cheating, they tell you immediately they want out, then after 6 weeks of disassembling the marriage, they never speak to you again. Last contact was 9 months ago and not a peep. Creepy, really.
She was also bereft of any kind of interests. She never read, or had favorite things, or talked deeply about stuff, or pursued hobbies. She spent all her free time playing games on her phone, reading celebrity gossip, and shopping. So so so much shopping. Her interests were my interests and she was fine with that.
You know what this might be a sign of, though? A fucking chameleon, someone who gloms onto someone and becomes that person, pretends to share in their interests, so they can infiltrate their lives and foster a deeper attachment from that target. Narcs do that. The Narc term gets thrown around a lot, but you can only check over half the boxes on so many "is your spouse a narc" checklists before you start to think "you know what, that bitch was a narc!" and carry that with you for the rest of time. Another thing they do is "love-bombing", and that also includes the aforementioned chameleon bullshit.
I had access to our shared Amazon account for weeks after we split and I saw her purchase activity during and a few weeks after the separation. This guy shared similar interests as me--I feel like I was replaced in some regard, which sickened me for a while--as evident by the shit she was buying this guy. He's also, apparently, an avid hunter because she bought him that kind of stuff, too. All this mere weeks after I caught her affair, a day which started with me 100% thinking she was on board the "we're going to love each other forever" train. The level of deception that this fuckface achieved disturbed me for a very long time. Anyway, her buying him shit is of course a sign of love-bombing a new source of "ego kibbles" as a lot of people in the Infidelity World call it.
I could go on and on, but really I just want you to keep thinking critically about the full relationship. See the trends, spot the bad behaviors that you ignored, adjust your thinking to cope and move on. It's amazing how much we ignore when we're in love with these people. When someone you would've DIED FOR, very literally, casually rejects you and then show zero fucking remorse while doing it, it does a number on you. Keep posting, keep talking it out, exercise and eat right, sleep as regularly as you can, and take care of the legal shit as soon as possible. There's light at the end of this tunnel of shit.
Edit: Adding onto RustyLife's post, mine also threw tantrums and acted extremely childishly when things didn't go her way. But she was very good at her job, mostly pleasant around my friends and family, and very much into physical intimacy (cuddling and such, not just sex), so she wasn't all bad. Partially why it was so hard to fully appreciate all the very bad (such as secretly going off her birth control to force a baby).
[This message edited by AbandonedGuy at 12:02 PM, July 17th (Wednesday)]