Thank you for the article EauRouge. Some of it certainly resonates with me.
I can also very much identify with the "do I really have this, or am I just a bad / defective person?" self-questioning. I am undiagnosed, and cannot imagine walking into a doctor's office and speaking about this. I've done so much reading about this over the last six months or so, and it fits, and it explains so very many things, but I still think: am I wrong? Do I just want to believe this? Is it an excuse for my many failures, for my inability to think, speak and act the way other people do?
I mentioned it to my mother, when we were discussing the child of a relative who has traits of ASD. I just dropped it in there - "I wonder, actually, if I have it." - expecting surprise or denial, maybe. Instead she did a head-tilt and went "Hmmmmm." 
She then pointed out that I am weird about eye contact and don't retain information unless it pertains directly to me. The eye contact thing I am aware of - it's weird and uncomfortable, I have to make a conscious effort to do it an appropriate amount, and I never really know if I'm doing it correctly or not.
As a child - I learned to read aged two, when my mum was teaching my older brother, by pottering around in the same room. I read a lot, constantly, and have pretty much always been able to spell perfectly. The only words I can remember ever actually needing to learn how to spell were "hieroglyphic" and "necessary". At school I remember being gently told off because I had started deliberately misspelling easy words in an attempt to emulate the other children. I had a series of "monogamous" best-friend-ships; I think I was quite well-liked and vaguely remember "allowing" the other girls to have a turn at being my best friend 
which sounds a bit awful, actually, but I don't remember any unpleasantness.
I had the ability to write poems with perfect metre and rhyme. It still jars me if I read a line of verse that doesn't quite scan.
However, I could and did tell lies. As an adult I dislike lying and feel very uncomfortable with it. But as a small child I was almost known for it for a time. Not creative lies, more flat denial of things that were known.
At seconday school I was much less of a ringleader - I made two close friends and we were a gang of three, very uncool but happy enough, and stayed on good terms with everybody else. Academically I did very well with little effort.
My DC are home now so I'm going to stop writing. I hope it is OK to use this space like this...I am sort of ordering my thoughts. I need to write a bit more, I think, about university - which I loved, but which brought out my issues, whatever they are, in quite striking ways - and afterwards, when I drifted and floundered and began to wonder why I was failing.