There's a story about one of the Companions of the Prophet that used to laugh and cry at different times, seemingly for no reason. The just of it is as follows. One day someone asked him why. "I cry when I think of burying my own daughter alive in the time before I became a Muslim, as was the custom. She reached up and stroked my beard as I was putting dirt on her. And I laugh because of another incident. The Qaraish had a law that anyone found without an idol would be punished. We were made to carry a small statue with us on our travels. One day, I was out without my idol and I saw some men coming. The only thing I had with me was some dates, so I fashioned an idol quickly out of dates and pretended to worship it. After the men left, I ate my idol. And that is why I laugh."