So, I had an incredibly fucked-up childhood in a toxic abusive environment and never really learned how to people.
When I was younger I was... abrasive, let's say. Or possibly just an insufferable prick. I would argue with people on the internet a lot and generate a lot of conflict - not from a desire to troll (as many assumed), I was just raised in a test-to-destruction environment where loud table-slapping debate was just how you learned things - kind of cage-match debugging sessions kind of thing.
This didn't make me many friends, understandably.
Anyway, decades passed and I learned to mellow out a bit, to go along to get along, and to develop some soft skills like y'know, tact, and... compassion for people's emotional investment in their intellectual position, if that has a name.
Well and good, the people I talk to don't generally want to strangle me, chalk it up as a win.
But increasingly of late I've been hearing disparaging talk of 'people pleasers', which as best I can tell seems to refer to people who do all the things I was yelled for not doing half my life: going along to get along, valuing other people's needs and emotional sore spots, taking a cooperative, defensive-driving kind of approach to social ineraction - and I am confuse.
I lack a proper framework to parse this all intuitively; I had to build my social skillset manually by trial and error, and things obvious to others remain somewhat mysterious to me.
I'm not actually ASD (just ADHD), but my lack-of-intuitive-grasp on certain things presents a similar profile. Can someone give me a longhand explanation of the border between not-an-asshole and people-pleasing?
I also grew up in an abusive home--but I had a freeze/flee response to conflict.
So, there are several "defense" tactics when it comes to conflict. Fight, which you grew up with. Freeze (do nothing and hope they don't notice you), Flee (leave the situation), and Fawn (people-pleasing).
When people say not to be a people-pleaser, they are generally talking to people who have an oversized urge to please as their defensive tactic. If you are a person where "fight" is your go-to, toning it down so you can properly interact with people isn't a bad thing. It's what YOU needed to do for YOU to gain necessary social skills.
But other people out there have "Fawn" as their defense mechanism. That is to say, whenever there's conflict, they try to placate other people as their technique to de-escalate. And this becomes a situation FOR THEM where they erode their own boundaries trying to please other people whenever in conflict. It becomes a problem when other people take advantage of them because they tend to fawn and give other people things too much, and it causes harm in their life where work/spouses/friends abuse their placating nature. At that point, people who "fawn" need to try to do what you did with your fight response, and set more boundaries and say "no" more often without placating.
A good portion of "general advice" on the internet does not point out that "context matters". But it really does, the patterns and personality and past of the person taking advice matters, and when it comes to someone who grew up in an abusive home learning how to master their defense mechanisms, different people will need different advice.
If you were truly as belligerent as you say before, I'd be honestly surprised if you over-corrected to the point of people-pleasing becoming a detriment, as it's extremely hard to shake these things. They almost seem to be inborn personality traits that are ramped up into extremes if one is in an abusive situation. I have a friend who had a journey similar to yours, with a "fight" defense mechanism mode, and he's done a TON of work breaking the "fight" response, but you can still catch him in moments where he goes into "asshole mode".
And I'm the same, I've grown and improved, but I still default to "freeze" or "flee" in conflict situations that are especially stressful. (My growth has been embracing a "fight" response when necessary, and also a "fawn" response when necessary.) Him and I made opposite journeys...I learned to be more aggressive because it was necessary, and he toned his aggression down (because it was necessary to avoid driving away people he loved).
I stepped away and thought of more things--so a response to my own reply, heh.
As for learning where to draw the line...you need to take a pragmatic approach to your own past responses to things. Stop and look at them with clear eyes, pretend you are a scientist analyzing data both good and bad, and don't cherry-pick your data, look at both sides of what happened...how many of your recent responses go overboard with "fight" in a way that doesn't give a clear benefit or align with your ethics? (And how many likewise do "fawn"?)
Like, fighting just to fight drives people away so that's not a benefit as you lose community and support, and fighting with (say) a customer service person you'll never see again for $2.00 turns you into a Karen and wastes time so that's not a benefit.
But haggling on the purchase of a house or a car might actually be a financial benefit (so long as you don't turn it on the underlings and place it where it belongs and don't go overboard with being mean just to be mean).
So look at your recent responses. How many fight for "bad" reasons that are small or petty or waste your own time, how many fight for "good" reasons?
Likewise, how many of your reactions people-please in ways that help you keep friends you actually want to keep, and how many start to be detrimental to you because people are starting to abuse your new habit of people-pleasing?
To learn where the line in your life is for either response, you need to look at what YOU'VE recently done, and figure out if that's the person you want to be, if the benefits/detriments make sense.
For example (example pulled out of my ass), if you go out with friends and pay for stuff for everyone SOMETIMES, that is one thing. If you NEVER do it because you're angry they're taking advantage of you...well, if you never do it, how could you be paying for everything "all the time"? How could that even be possible? Sure, the anger is there, but is it based in reality? Might be you're just angry to be angry--and it's good to look at that. Fact-check emotions against reality to re-calibrate and see what's going on.
But by the same measure, if you over-correct because you feel bad about being an asshole in the past and you desperately don't want to be that person...you might be paying for everything all the time...which actually IS unfair to you, and if you examine a situation and find you've over-corrected and this is happening, an appropriate balance might be to scale it back. But you want to CHECK and look at your pattern across time to see if that's going on.
(Patterns across time tell you more than isolating one event out of context.)
You'll probably find instances where you FEEL one way and want to fight/fawn/(freeze/flee), but to continue to grow you probably need to stop and look at your recent patterns and fact-check your emotions against what really happened.
For me, since learning to "fight" was a part of my journey away from "flee/freeze", I tend to reserve "fighting" for situations where either A) I'll get genuinely financially fucked if I don't (not just a dollar here or there, but something that'll affect food/rent/real-life survival stuff), or B) I'm interacting with a community and there's toxic folks coming in. Sometimes a community with toxic people simply need someone to stand up and call it out to counter the bystander effect, then people will rally behind you.
Also, a note: When you draw a boundary, even if it's a very rational and reasonable one, it is not uncommon for SOMEONE to get upset by it. This is not the same as everyone getting mad at you because you're constantly an asshole. Again, the proof is in the pattern...if no matter what you do people seem constantly angry at you, that's probably you. But if that reaction to you has stopped, but a few people get upset if you actively set a boundary on something--that's human nature. There are OTHER people out there who definitely want to take advantage of everyone around them, and that's sometimes you, so if you set any sort of boundary at all no matter how rational that'll still be "too much" for them.
That's not necessarily a sign that you've "back slid", it's just that 20-30% of people are shitty people no matter what.