I have borderline high-functioning autism myself. Regarding "special talents" (with me anyway) - it comes and goes. I can't switch it on/ off. Regarding the chairs if there were 6 rows of 8 chairs it isn't that hard to count. The ability to remember musical melodies isn't that difficult - and can be learned. It's part of most musician's training to be able to memorise not just a riff but entire pages of music. If you've taken a music exam you have to sing back a few phrases played to you - which is not far off playing them. I get the tension headaches too - one of the downsides of the frustration caused by having a communication disorder and being misunderstood.

In my own experience I remember a migraine I had come on at work and it transformed me into a savant (of sorts) by giving me a mini Tourette's episode. I couldn't actually tell my colleagues in so many words why I was being a bit odd (apparently muttering "motherfucker" every third word is normal for me when I'm working on something tricky - who knew?) but I developed an amazing ability to communicate my predicament by pointing at my head, grimacing, and saying "shit motherfucker gnnn!"

Who knew that talent lay latent within me, just waiting for its release through the method of blinding and nauseating pain?