I used to laugh like that in a dream. Some situation in my dream seemed so funny that I started to laugh, and woke up from the fact that I laughed loudly in my sleep. Waking up, it's still funny, and for not to scare the sleeping neighbors with wild laughter in the night, I had to laugh in the pillow, tears streamed with laughter, and it seemed to me that I had never experienced anything so funny. Sobbing with laughter, I was lost in sleep again. And in the morning when I remembered what I was laughing at, I was perplexed - what could be funny about the fact that a butterfly sat on a flower?