My mind is running out of faces

I began a new job today. A fairly boring job for a very basic wage. The person training me however is a dead ringer for someone in my past who through the magic of facebook I have found myself reunited with. With this in mind I know full well the person I have been sitting with is not said person from my past but (probably to do with aforementioned problems with sleep) I have spent the whole day thinking 'oh ****! what are you doing here teaching me this stuff?' I know now how the various tales of vampires reunited with long dead people from their lives must have come about. There are obviously a finite number of facial combinations and probably in your subconscious, your mind must fill in the blanks and I've noticed more and more that my mind is running out. unfortunately exactly the same can be said of personalities. Very often I am sat with a new person for a few days and I know I've met them before albeit with a different id, memories, bodies etc but I know exactly what I'm getting. Experience perhaps? Why old people claim to be a 'good judge of character' and why young people so often feel unfairly judged by old people.
Crap! I just called myself old didn't I? ah well you know what they say (they talk a lot don't they) if the cap fits, fuck it!