Plato's Great...Great Grandchildren

I met Nick last week at a friend's party. We talked about this and that for a while until I noticed that his big smile never left him. At such hard times, how did he manage to keep on smiling?
It's finally official,” he told me. “Seventy years ago, the registrar made a mistake. My real family name is Paleologos, not Paleologou, as we are called.”
Can a single letter make such a big deal?”
A huge one. You see, my family's origin is from a village close to upper Kardamili in Mani. And that's where the brother of the last Emperor of Byzantium hid from the Turks and settled down. The dynasty of Paleologos was the longest in Byzantium. I must be their direct descendant!”

Reader, I am not a young man any more so I have watched myself bleed many times. And even though I don't suffer from colour blindness, I can't be certain if my blood colour is closer to pink than black. There is one thing however I am damn sure of: not once did it appear to be blue. Unlike smiling Nick I have no claims to royalty. But ever since I was in high school, I had this bug inside me. Where did I come from?