No matter how familiar we used to be with each other, as long as we are apart then we become strangers.

不管如何熟悉我们曾经是彼此，只要我们是分开的然后我们成为陌生人。

youdao

We"ll have friends, and have become strangers to each other, "This is as it ought to be.

我们会有朋友，彼此之间会变成陌生人，理应这样。 我们是两只船，都有自己的目的地和路线。

youdao

We meet when we are strangers but depart when we are familiar with each other I will never forget you and please remember me and come to see me occasionally. May you be happy and smooth in advance.

我们相逢在陌生时，分手在熟悉后，我永远不会摸去对你的记忆，请你也偶尔想想我，看看我，预祝万事如意，幸福快乐。

youdao

As seems to be so in most Swiss villages, complete strangers in Kandersteg greet each other as they walk past.

BBC: Swiss movement