From Salon....

Jan. 29, 2002 | If you've ever wondered where Michael Jackson finds the inspiration for his most heartfelt love songs, the answer is at hand: He gets it from playing with kids.
In a strictly innocent way, of course. Like, say, the water balloon fight that moved him to write his recent power ballad "Speechless," a plaintive song of a love that dare not speak.
(Sample lyrics: "When I'm with you, I'm at a loss for words. I don't know what to say. My head's spinning like a carousel. So silently I pray. Helpless and hopeless, that's how I feel inside ...")
"I was with these kids in Germany, and we had a big water balloon fight and I was so happy after the fight that I ran upstairs in their house and wrote 'Speechless,'" Jackson tells Vibe magazine.
A balloon-inspired burst of inspiration, you might call it.
"Fun inspires me. I hate to say that, because it's such a romantic song. But it was the fight that did it," he says. "I was happy, and I wrote it in its entirety right there."
He just has to know how this stuff sounds.