I was shocked at how little Daniel Tammet and I have in common regarding our perceptions of the world. I wonder if he would be equally clueless concerning the way my mind works, if I were to try to explain it.
I was talking with a friend the other day about pitch. She claims not to have perfect pitch, but she can tell where any note is on her instrument, and insists that as long as you can name a note, you can commit that note to memory and always be able to tell what it is. She was surprised when I told her that no matter how hard I try (and I have tried, believe me: my three brothers all have perfect pitch), I haven't been able to develop pitch recognition. I often imagine pieces in my mind in the right key, but if I were asked to name that particular key (and if I didn't already know the name of the key), I wouldn't be able to do it with any kind of certainty.
My father once assured me that even though I don't have perfect pitch, I do have other things.