Rainfall discussion

When you start a conversation about one topic but other topics end up just falling out of nowhere like a sudden rainstorm.

"Hey did you talk to your mom about getting her spaghetti recipe?"
"Yeah, but we ended up also talking about nuclear power, cloth diapers, and who would win in a fight between John Cena and Sarah Palin. It was a real rainfall discussion."

rainfall discussion

1. Meaning to type "rational discussion" on a smart phone, but misspelling "rational" enough to make your phone think you wanted to discuss rainfall's effects.

2. A discussion on the effects of rainfall

Will Smith: Man we need to have a rainfall discussion.

Snoop Dogg: Fo drizzle!