Obsession with twngan

Let me celebrate the imminent new year by a triple post. To me, this is something quite complicated. I've got an email from an old friend X from high school whom I have not got in touch with for 4 years. He told me he got married with Y 6 months ago in US. X and Y have not been in the same elementary or high school. When X was preparing invitations for a wedding banquet in Hong Kong, he came across a name Z of a high school classmate that Y recognizes as an elementary school classmate. X also remembers vaguely that I am from the same elementary school with Z, so he emailed me and asked. It turns out I still remember all of them, and it is actually two people I know got married...

I don't know about you but I find this kind of relationship very interesting.