Over Thanksgiving, one of his friends from Singapore was over for dinner and he tried to explain Greece to her. Only he was explaining Classical Greece. To a Chinese woman who had never heard of Alexander the Great and had no idea that Western culture IS Greek culture. In the time it took to wait for dinner. It was a tall order. It also had nothing whatever to do with why modern Greece could threaten the world financial system.
If I wanted to explain how modern Greece could threaten the world financial system, I would explain it rather in the same terms I explain WWI. It was like a bunch of rock climbers, all roped together to ensure that if one fell, all the rest would fall too. And yes, I realize that real rock climbers would be indignant at the comparison. They rope together so they can catch one who falls. Done properly, it works. If one rock climber pulls down others, it shows that they don't know what they are doing and shouldn't be climbing in the first place.
So let me refine the analogy a little. The euro is like WWI, which was like a bunch of wanna be rock climbers who didn't know what they were doing, climbing a much tougher climb than they were qualified to take, all roped together thinking they could catch any one who fell, but actually doing it all wrong and just ensuring that anyone who fell would bring the others down. So the clear lesson is, don't go rock climbing unless you know what you are doing.