Some of us have been officially diagnosis others are self diagnosed.
An official diagnosis relies of the training and professionalism of the doctor or psychologist involved. Self diagnosed relies of the intelligence and objectivity of the individual. Both methods are open to error.
But there is a third way to get diagnosis.
Diagnosis by association:-that is to say if we log on AFF or similar website and feel at home, relate well to the people on the site; share a similar thinking style and a significant amount of behavioural quirks. If you see the world in the same way as they do, then the odds are you’re an aspie.
Apologies for the poor spelling in this post…I've just read it back and its somewhat incoherent.
Also please note that diagnosis by association is very subjective and I didn't intend to suggest it should replace standard diagnostic techniques.
Diagnosis by association:-that is to say if we log on AFF or similar website and feel at home, relate well to the people on the site; share a similar thinking style and a significant amount of behavioural quirks. If you see the world in the same way as they do, then the odds are you’re an aspie.
To me that's the same as self-diagnosis, only more open to error as it is based purely on subjective values and doesn't take facts (such as development) into account.
Also please note that diagnosis by association is very subjective and I didn't intend to suggest it should replace standard diagnostic techniques.
Oops I should've read that first 
I still think this method is more suitable for deciding whether someone makes a good friend than for any sort of "diagnosis" though.
Diagnosis by association:-that is to say if we log on AFF or similar website and feel at home, relate well to the people on the site; share a similar thinking style and a significant amount of behavioural quirks. If you see the world in the same way as they do, then the odds are you’re an aspie.
To me that's the same as self-diagnosis, only more open to error as it is based purely on subjective values and doesn't take facts (such as development) into account.
You don't think it takes one to know one? 
You don't think it takes one to know one?

Not as such, although I have noticed that quite a few people working in the area of autism have autistic traits themselves, some even have AS and a few have close relatives with AS or autism. Or if they don't have AS traits then they often have some comorbids.
The lady who diagnosed me is face blind for example, and a friend who is quite well-known in the field has a son with autism. The lady who leads the local autism group has a few 'quirks' of her own (and loves to sit and watch the washing machine for example).
So yes there is a tendency to be pulled towards people with similar characteristics, I just don't think it works on forums. There's a reason why doctors are often sceptical about people walking into their office with the words "I read something on the internet and now I'm convinced I have it".
There's a reason why doctors are often sceptical about people walking into their office with the words "I read something on the internet and now I'm convinced I have it".
(chuckle) I go back and forth. I read the list of traits and some of the posts and I think "wow, that's me" and I feel pretty certain that I'm an aspie. The peices seem to fall into place.
Then I read a forum or a book about someone who is much more profoundly affected and I think. "okay, I guess I'm not"
Though, my closest friend keeps pointing it out to me whenever I exhibit one of the traits or am struggling with the the the world. He says: "Yes, you really ARE that way." (He has a degree in psychology. Doctorate I think)
(chuckle) I go back and forth. I read the list of traits and some of the posts and I think "wow, that's me" and I feel pretty certain that I'm an aspie. The peices seem to fall into place.
Then I read a forum or a book about someone who is much more profoundly affected and I think. "okay, I guess I'm not"
I get that a lot with those texts by experts who give examples of some very serious social faux-pas and make me think "Jesus I'm never that 'thick'". (Mind you I still don't get why getting upset about people with more than 10 items in the 10 items or less checkout queue is a bad thing. I can see why making a tit of yourself to distract the cashier from noticing that someone you like has 11 items instead of 10 is wrong, as is described in some daft quiz by the lady who made those social stories, but I don't get those social stories anyway. What's the point of memorising daft motivational phrases and rules when you have no clue how to apply that knowledge in the real world?)
OTOH I read stuff like "Pretending to be Normal" and think "How frigging self-aware was that woman as a kid? If I'd been aware of even a fragment of what she was aware of I wouldn't have been stuck in my own world so much."
Though, my closest friend keeps pointing it out to me whenever I exhibit one of the traits or am struggling with the the the world. He says: "Yes, you really ARE that way." (He has a degree in psychology. Doctorate I think)
That's really handy to have. My partner is the same, he doesn't say "Oh you're being autistic again" and doesn't mention autism but he does point things out to me that I do without realising, and mostly those are things that you read about in textbooks on autism.
By the way I think it is useful to read as MANY autobiographies of autistic/AS people as possible, because it really helps to see how much difference there is.
There is likely to be a bunch of stuff from each that you identify with, but rarely a single book that describes PRECISELY how things were for you. People's circumstances and symptoms and skills etc. differ far too much for that to be possible.