Obligatory Disclaimer Things
1) I am one person with borderline personality disorder! I am not the expert! This is just what it feels like to me, given my background, coping mechanisms, etc. Also I have comorbid generalized anxiety disorder and social phobia; someone else who has different comorbid Brain Issues (or, like, no comorbid issues at all? which is apparently a thing for some people) will have a different experience. You should not assume that all borderlines have the same psychology I do. People with BPD who have different experiences than me are welcome to share in the comments.
2) Please note that I have borderline personality disorder, and I will be reading the comments. So if you say that people with BPD are empathyless abusers who are incapable of love, you are saying that to me. I will delete your comment and then I will probably go cry because Jesus, people.
3) While this should not be super-triggery, I do go into some detail about the mental processes of a person with borderline personality disorder and mention suicide and self-harm.

To me, borderline personality disorder feels like it has three different aspects: fear of abandonment, lack of a self-image, and really really wild mood swings.

The fear of abandonment part is probably the part that ends up hurting other people the most. I literally have panic attacks at the thought of not having any friends; I am desperate to keep everyone from hating me or being upset at me because if they do they will leave me and then– well, it’s kind of hard, as a borderline, to complete that sentence, because the only answer my brain tosses up is “and then everything will be awful and hurt forever and you will probably stop existing.”

Every conversation I have feels like a tightrope walk where if I say the wrong thing then I will be abandoned forever. I’m manipulative, sometimes, like a lot of borderlines. I need attention and validation; if I’m not reassured often that someone likes me, I’ll tend to conclude that they hate me. I get very clingy and needy and then run away because oh god I’m too clingy they will hate me now. I test people a lot. Do you say hi to me if I don’t say hi first? Do you notice if I look sad and ask if something’s wrong?

There are a couple of things I do when I think someone hates me. The first is to frantically propitiate them: to be kind enough and smart enough and sexy enough and do everything they want and never ask for anything that might inconvenience them and then maybe– even if they don’t like me– they’ll just put up with me. The second is to hurt myself (if I’m hurting they will pay attention to me!) or the person who hates me (if they stay with me even if I’m hurting them they must really like me!). The third is to decide that I don’t like them and so I am not upset that they want to leave me. I am really good at that. I don’t even have anyone I’m currently in contact with whom I’ve known for more than two years.

Like a lot of borderlines, I’m bad at the concept that people still exist when they’re not in contact with me. I forget people when they’re not around. If I have things that belong to someone, I can remember them, which is why I tend to collect presents that people I love have given me. I’m also bad at the concept that people can be things other than “perfect paragons whose feet I should kiss” and “scum of the earth.” You’re perfect if you love me, and you’re scum if you might leave.

Another big thing in borderline personality disorder is… well, the DSM calls it “affective instability,” and your more poetical psychologist-types call it “having no emotional skin.” I feel everything more intensely than a neurotypical person does. A cute picture of a sloth can leave me so happy I’m incapable of forming words. A C on a test can make me suicidal. (Lots of borderline people get into really intense rages; I don’t. In fact, I can count the number of times I felt anger not at myself on one hand. You see, anger is a bad emotion and it will make people mad at you and then they will leave.)

Like a lot of borderline people, I’m impulsive as hell. In the moment, the feelings are so intense that you can’t imagine not wanting to destroy all your possessions to punish yourself for being such a bad person. The idea of waiting a few minutes to see if it still sounds like a good idea is ludicrous. After all, the feeling is so big, surely I’ll feel it for the rest of forever. (This, despite the fact that my emotions rarely last ten minutes.)

Since little emotions are incredibly intense, big emotions are even more fucking intense. I dissociate under stress, which means that everything stops feeling real to me; I’m lucky, because at least I don’t have severe paranoia or psychosis. On the other hand, when nothing is happening to make me feel anything, it all feels kind of sad and empty compared to the big feelings that I normally have. That’s another reason I get impulsive: anything to feel.

The third thing is unstable self-image, which I developed a really good coping mechanism for, so I don’t experience it as much as a lot of other borderline people do. Most people… kind of know who they are. They have a sense of self. Borderlines don’t. Some of them end up clinging on other people for a sense of self, or rapidly changing everything about themselves. Me, I have labels. People have told me that I’m a geek and a skeptic and a feminist and kind and loyal and tough and smart and poly and queer and genderqueer and forgetful and flaky and shy and obsessive and so I have all these words and they kind of pin down who I am.

I said “people have told me” deliberately. I don’t know how to know things about myself, other than people telling me. I tend to stare at personality questionnaires going ??? and then having to ask if the answer fits me because I have no idea who I am. I also get very distressed when people contradict each other about my personality traits because how will I know who I am if people disagree about it?