Rules of Haiku

I occasionally dabble in haiku, an ancient Japanese form of poetry. It's supposed to be about nature, but balls to such restrictions. You find haikus can be about anything these days. To explain how to do it, here's a haiku... about haiku.

Five syllables first
Seven syllables follow
End it with five more.

Well. Isn't that the most evocative, heartfelt thing you ever read. Maybe we should stick with nature-based haiku after all. God, I was bored when I came up with that.