Interesting, I didn't know that. I was intrigued enough that I had to look up the original quote[0] as I had my doubts. I was able to easily find it though, is from a 10/12/2012 interview with Wired.

Perhaps he's gained some humility since then; I'm still very inspired by him regardless...

[0] http://www.wired.com/2012/10/ff-elon-musk-qa/