"I am focused on task x and cannot talk to you".

Does he have a job to do or is he just there to pester people with smalltalk?

I’m torn because I want to tell him to leave me alone, that I don’t care about his life, but considering the ‘offense’ this seems too much and knowing me I’d immediately regret it and feel bad about it.

Imagine someone has a huge booger hanging out of their nose. It might be embarassing that you point it out to them, but it's a lot more embarassing if they walk around with the booger hanging there. It's the same with this. If you're polite but direct, there's nothing to feel bad about, you're helping the guy learn where the line is.

Take up skiing and make that your entire personality

Show him your Warhammer figurines

They sound a lot like an ex colleague of mine who had aspergers. They latched on to me because they got promoted to a different team in the same office as me when i got promoted and they would not stop talking to me, and about the most inane and mundane shit. Stuff i didnt gove a fuck about

I would be polite i would answer and engage in the conversation but if it had been too long and i felt managers eyes in the back of my head i would just fizzle out and start to turn back to my screen and say something like "ok, well, i need to get on" and they would go away.

I believe they were this way because of aspergers. They could never tell when i was uninterested or when i was busy with something. They didn't pick up on social cues. They just kept talking.

I wonder if it's a similar reason with your colleague?

Why am I like this?

Because different people are different. I am the same. I could not give 2 shits about my coworkers personal lives.

Us dudes are thick as bricks, put him on the backdoor by using some of these.

I'm in the middle of something, I wish you would stop interrupting me.

Dude, stop interrupting me.

No seriously, if you keep interrupting me I will have to talk to management about it.

Just tell him you don't talk a lot because you need to concentrate at work and you always keep it professional because you wanna separate work and private life.

Small chance it might be awkward for a bit but he will respect it. Unless he is an asshole then you don't owe friendliness.

I'd recommend practicing being direct, polite, and consistent. In the end you can't control his actions but you can control yours. If you need help then get help from a capable coworker or manager. Don't waste any time or energy feeling bad about it.

I’m torn because I want to tell him to leave me alone, that I don’t care about his life,

Tell them to leave you alone, that you don't care about their life.

I'm 100% serious. Just be honest if thats the way you feel. It sets up boundaries and if they are a sane person, they'll respect you for your honesty.

Have you tried telling him.. to leave you alone?

You're not responsible for meeting this man's needs. You don't need to trick him. "Please leave me alone." If he does not do this simple thing, then you have not committed any offence and you can train yourself not to feel bad about it. You already meditate, so you might make your tendency to feel bad about this into an object of meditation.

Unfortunately, you can't control his behavior. He might still try to sit down next to you and talk to you about things that don't interest you. I don't know what more you can do than ask him to stop doing this and hope he complies. "Please stop doing this. I'm just not interested. I prefer to be alone." It is compassionate to say nothing more than this.

As for why you're like this, that's very likely because someone taught to you to care about other people's feelings and didn't teach you that their feelings are not your fault. This seems pretty common.

The stories you tell yourself about why he does this and the stories you tell yourself to explain your own behavior... they probably don't help you much, do they?

Peace.

Well, sometimes people just don't ever get it and they need to be told to fuck off in very blunt words. I think that usually poisons the well and dries up further conversation, permanently. But I'm not sure if this is the case here. And that strategy possibly comes with other severe consequences. So I won't recommend it. The mild version of it is to just be direct and honest, skipping any overly kind phrasing.

Another strategy would be to have someone else talk to him... You yourself seem to be getting nowhere. But maybe he listens to other people, or they're somehow more gifted to get through to people like him.

What also sometimes works (depending on circumstances) are large headphones. They might be part of your work anyways, if you're doing online-meetings in the office, or you are allowed to listen to music... Either do that and you can't hear him anyways, or just put them on all day and say "Huh?" 200 times a day and see if he picks up on it. Though, this might not work if he's stupid, as well. Or he might start tapping you on the shoulder and invade your privacy even more... Idk. But headphones have worked for me in various situations. Especially if they're big and noticeable.

There’s something called “The Grey Rock Method” you may want to check out. This link is just from a quick search, there may be better sources out there:

https://psychcentral.com/health/grey-rock-method

Holy shit, this is the very same people that later will tell you about how they will "eat the rich" and "deny, despise , defenestrate" (or whatever) every CEO they encounter.

All the meanwhile being incredibly socially stunted and so utterly incapable of even being direct with someone and talking over a perceived issue at work, one of the safest environments they'll have access to for human interactions.

Totally unhinged, dissociative and disconnected from reality behavior.

first you tell him you don't like to exchange more than a few sentences per person. then you tell him, he exceeded his limit for years, so you will not talk to him any more, except if it's a real business matter. then you don't reply, unless it's a real business matter, for the next few years.

Offend him, who the fuck cares. Dude obviously doesn't give a shit about your time and energy, or boundaries. He doesn't respect you, so he deserves no respect in return.

Fight fire with fire. Figure out which topic he doesn’t care about, and start talking about it all the time. Like, literally all the time when he is in the vicinity.

Could be a new hobby like flying a kite or an obscure interest like the history green colors used in the textile industry. Ideally, you would pick something you can imagine yourself being passionate about. Look up some videos on how autistic people talk about their favorite topic, and you’ll get the idea.

"Excuse me"?

"Pardon"?

Blank look. Shrug, turn around, go back to reading.

Whenever he asks you something start off by staring at him with a blank emotionless stare for an uncomfortable amount of time, (20 or 30 seconds or so) tilting your head from side to side while you make eye contact with him and finally give him a simple one word response. If he continues talking keep direct eye contact and start making confused expressions on your face (like why are you still talking to me) then do everything you can to make the situation as awkward as possible. If he starts talking about himself or family or whatever make sure you interrupt him as much as possible even talking over him if necessary. Make up a weird uncomfortable story or start rambling on about some wild conspiracy like birds aren't real, the illuminati are controlling people's minds or maybe see if he'll come with you to a scientology seminar, the weirder the better.

Are you lactose intolerant? Can you fighter or the ideal amount of milk to drink such that you get the death toots but not the vanilla sharts? Next time he stops by, send him a stinky. A really foul one.

"I get frustrated if my attention gets pulled away from what I'm doing, that's why I focus on my current task instead of talking to you guys"

Have you tried gushing?

Not just responding, and having a busy conversation, but just not stopping, even interrupting him.

It wouldn't be my first choice, I prefer direct honesty, but you already tried telling him you're working.

You could try even more directly saying that you don't want to talk casually at work, but that requires not doing so with anyone, or you might as well just tell him you don't like him and be done with it that way. Which is an option. He is someone you don't like, but I assume you're wanting to avoid that because it's work, so that's the absolute last option.