Expression

There is a memorable line from Leslie Cheung's Passer-by Dragonfly (路過蜻蜓):

哭 我為了感動誰
笑 又為了碰著誰

It just demonstrated the similarity of crying and laughing. It was an expression from mood: when you are sad, you cry; when you are happy, you laugh. However, sometimes you will cry because you are so happy and you laugh because you can't be more sorrowful. What's more, they are external to others.

But then, it rises an interesting question: what is it for, if there is no one out there to hear you cry or laugh? Apparently it sounds silly, if not stupid. But then, it is something we do: hiding ourselves by locking ourselves, and then we burst into tears. No one recognized our sadness. We feel good about it. Therefore, we cry.

So it probably gave an incomplete answer to the line. Cry, because we wanted to move ourselves.