There are many countries in the world where they don't really record age of people so because of it, it's rather easy to cheat and claim to have a different age. He may be 20 for all we know but given his stuff, he would have a higher value if he claimed to be 18.
You see the same thing quite often in Soccer in Europe, where you have players who came from Africa claim to be a certain age and then by the time they are "30-35", they look like they are 50 and can't play.