I don't think it was too long. I've done the same sort of thing, but just in my mind, many times and had pretty well determined I had Asperger's. Taking the quiz on this site nailed it down for me (although I have still not been diagnosed by someone who could confirm it).

You have to realize, I'm 69, and five years ago I had never even heard of Asperger's. But as soon as I started reading about it, many of the pieces I had long wondered about began falling into place. In no way do I feel bad about what I have been all these years. It has given me a better understanding of myself. Plus, one of the advantages of my discovery is that I now know I'm not alone -- there are a whole lot of nice people very similar to me.