I have always been interesting in Matching patters - in anything (even faces).
I actually realized that when I took this aptitude test when I was 14 - they told me that my pattern-matching skills were exceptionally good and that I could be either an architect or a computer-engineer!
Just the other day, I caught myself trying to distinguish between the two pics that made the "Turkey Hunter" at the Museum. I notice that I do this quite often!
And then there was the time when I first saw the "Ghosts" video by Michael Jackson - a long long time ago - something about the fat professor (his eyes) in the video made me believe that he too was actually MJ and it was not until a few years later when I came to the US and saw the complete making of the video that I found out that I had been right all along :)