I don’t understand why I’ve never been liked by people I’ve met

Do you speak to them the same way you do on here?

How do you measure someone's feelings towards you?
Do you believe that's the best (or indeed only) way of measuring this?
Is it possible for a person to conceal their feelings from you?

I don’t think everyone goes around constantly thinking about and hating me, I’ve just never had someone have positive feelings towards me, like they might only have one interaction with me, think “I don’t really like her” and never speak to/think about me again.

Okay
And what about the answers to the questions I asked?

I measure someone’s feelings by the way they interact with me and choose to avoid interacting with me, and it’s possible for people to conceal their feelings but I can’t think of any reason why someone would conceal positive feelings towards someone by pretending to have negative feelings towards them

So you're perceiving the absence of interaction with other people as them not liking you?

I’m perceiving *avoiding* interacting me as disliking me, (edited the title to better convey what I actually meant), I don’t think everyone goes around constantly hating me, they just passively dislike me without it occupying any significant space in their mind.

How do you know that someone not interacting with you is avoiding you deliberately?

It’s pretty easy to spot and it’s extremely hard to feel truly neutral about someone you meet/know and genuinely not even have the tiniest positive or negative feeling towards them, like not even a “she seems nice” or an “I don’t really like her”

Right, and the answer to my question?

Lol, what the title says. I’ve never met or interacted with someone whose feelings towards me have been anything other than mild dislike/disdain to hatred.

How do you measure someone's feelings towards you?
Do you believe that's the best (or indeed only) way of measuring this?
Is it possible for a person to conceal their feelings from you?

It's normally all about that ever-so important First Impression; you never get a second chance to make a first impression... and first impressions last.
When you meet these people, how do you act? Do you take an interest in them (e.g. find out what they've been up to; how their day / weekend has been; etc.). How are you when you talk to them? Are you "animated" (i.e. lots of facial expressions and mixed tone of voice) or do you stare like a psycho?... or do you avoid eye-contact? Do you stand too close to people when talking? When they are talking about XYZ, are you listening to what they're saying?... or do you talk about yourself and how wonderful you are?
One thing people do when they're comfortable with each-other, is something called "mirroring". No, I don't mean walking around with a mirror and flashing at them lol, I mean they adopt a very similar stance / pose when talking. It something people do unconsciously, but it does show a connection / rapport with the other person. Therefore, next time you're chatting, take a note at how your and their positioning is (e.g. positioning of arms, legs etc.). If their pose is similar to yours, then I'd say they're OK with you, and this is mainly in your head.
Having said that, certain things may "alienate" you from the group. For example, how you may behave on a night out... I don't know how old you are, but when most people go out for drinks, they tend to buy rounds (i.e. one person gets all the drinks for everyone else in the group, and they take it in turns). If there's someone who is an expert at avoiding getting the drinks when its their turn, then other people in the group can pick up on it, they talk about it and slowly ostracise that person (it starts by not inviting them to or including them in group activities... and ends with everyone not talking to them. This is just one example, but it can happen in all sorts of ways.
Not a definitive answer... but hopefully this gives you a few things to think about.
@04MR17 Maybe it's just your avatar... but whenever I read your posts, I'm hearing them in the voice of Mr Mandela (is that a good or a bad thing? 🤣)

To which question? How I know people are deliberately avoiding interacting with me? It’s hard to explain and would be even harder to prove, but after a whole life of experiencing it, I know it’s there. And even if the people who I believe to mildly dislike and avoid me were actually just completely indifferent towards, the edited title of my post is still true.
I don’t believe everyone is constantly maliciously out to get me, I’ve just never had someone feel positively towards me, the best I can hope for is people not interacting with me because they don’t even realise I exist.

Lol, what the title says. I’ve never met or interacted with someone whose feelings towards me have been anything other than mild dislike/disdain to hatred.

You say it's hard to explain, but please try. Because if you can't articulate why you believe someone is avoiding you (which is one of the key features of the question you're asking) then that makes it very difficult to try to understand the entire thing.

honestly sometimes it could just be overthinking and overanalysing certain interactions. It could also just be because you interacted with them for the first time and so its just awkward, that does not necessarily mean they don't like you they probably found their first interaction with you awkward.
The more you get to know them and the more they get to know you is how you can truly tell if people acc don't like you.
I hope i explained that well sorry if it doesn't make any sense

I can just tell within the first few minutes of someone meeting me that they’ve decided I’m not someone they want around, like they leave me to entirely carry the conversation or else sit in awkward silence and from then on they choose to not interact with me at all when they interact with (for example) everyone else in a class