我与他仅仅是点头之交。

I barely know him.

干吗算我？我们只是点头之交而已。

Why do you want add me in? We are just bowing acquaintances.

他是点头之交，我连他的名字都不知道。

Again, he is a nodding acquaintance, I don't even know his name.

一个有许多点头之交的人却没有很多真正的朋友是很常见的事情。

It's common that one who a nodding acquaintance with many people doesn't have many true friends.