You can know, intellectually, that other people think in ways different from you. You can have what you think are good models of other people in your head. You can even find you predict their actions and concerns and ideas a lot of the time.
But that doesn't mean that you understand how other people actually think.
Ever. Anyone. At all.
And sometimes you come across a big wodge of someone else's thought processes, and it stops you right in your tracks. "This doesn't make any sense," you may think. "How can you get to X from that G? Who would actually make those connections?" But you know someone did: you're reading the proof.
Allie Brosh is really good at clearly depicting the way she thinks. She did that brilliantly in her book of illustrated essays (semi-comics? what do we call what she does?) Hyperbole and a Half, nearly a decade ago. And she did it again, in the extended sequence of essays that form her new book Solutions and Other Problems.
The difference is that Hyperbole was a like a hot band's first record, collecting all of their hit singles - things you may have already heard, or heard parts of, in passing on the radio or in the background in some movie. It had a lot of great material, a lot of strong essays about how Brosh dealt with moments in her life, but they were generally separate pieces.
Solutions is a concept album, clearly designed as a single thing. It is a book telling a sequence of events, mostly true, selected and organized and contextualized and given weight by Brosh. It is a story organized inherently by the way she thinks about things, focused and precise in its Allie Brosh-ness.
And Allie Brosh thinks about a hell of a lot of things vastly differently than I do. I'm not trying to claim I'm the model of the world, or better at being neurotypical - but my mind is the only one I have, the only one I really understand, so it's the only measuring-stick I can use. 
Brosh doesn't diagnose or label herself in Solutions, so I won't try to do so here - there were pieces in Hyperbole about her clinical depression, but there's nothing that focused here, nothing specifically about mental states and diagnoses. Instead, it's a view of the world entirely from within Brosh's head - it felt to me a little like the essays in Hyperbole were Brosh trying to translate her worldview into, well, call it Average-ese, the broad consensus sense of reality, and Solutions is instead pure Brosh from the get-go.
And pure Brosh can be odd and disorienting. To me. I have no idea what you will think. Maybe everyone else in the world thinks more like Brosh than they do like me; that's entirely possible.
And I never would have thought that without Allie Brosh.
What is Solutions about? It's about being Allie Brosh, about her family and her childhood and the animals she knows and how she interacts with other people (or, a lot of the time, avoids doing so). I found myself being stopped short every few pages - sometimes multiple times a page - to say "What? Why? How does that even follow?!"
If everyone were capable of putting their thought processes down on paper like Brosh can, the world would be more comprehensible. Vastly weirder, too. But knowable in more basic way than it currently is.
I say that. But reading Solutions also teaches me that I really don't understand. Even after five hundred pages, if there was a quiz on the last page of "What Would Allie Do?" I bet I'd get most of the questions wrong. And that makes me think my models of everyone else are equally flawed.
But that realization is a good thing. We have to know what we can know first.
I often finish up, when I write about books here, by trying to describe who would or might want to read a particular book. The world is vast; we're all interested in different things. But Allie Brosh is something special. I'm sure there are other writers who can illuminate mental states as well as she can -- some academics, some science popularizers, some other memoirists in other formats. But Brosh combines that clarity with what feels to me like a unique viewpoint. I think we all need this. I think we all can benefit from this. And Solutions speeds by, for all its 500 pages.
So read it. Whoever you are, wherever you are, however you think. Maybe you will find yourself here. Maybe you will think she's weird in the same ways I do and maybe you will think she's weird in entirely different ways. Maybe we'll all think each other are weird in increasingly baroque ways.
We're all human: it's entirely possible.
 I'm not unacquainted with social anxiety, for example. I used to hide in hotel rooms at SF conferences, psyching myself up to go out and actually talk to people. It would even work, once in a while. Some of the worst moments of my life were trying to find someone, anyone to have dinner with at some random convention - and I was a guy with an expense account, which you'd think would make it easier for most people. For me, it did not.
I once physically refused to go into a restaurant at all, surprising my wife, sitting down on a curb outside once I realized it was family-style and I'd have to sit next to strangers and pass dishes around. And I made that reservation.
If anyone's mind is "typical" or "normal," it ain't mine. Even now, years after other things in my life burned out those fears and anxieties, I wouldn't claim to be anybody's icon of anything.