It's all been said/Did I make this up?

I would like your help in determining the origin of a quote. I'm sure I read this somewhere (and maybe my brain stole it as its own) but has anyone ever heard the quote:
"There are two types of people in the world: Those who think there are two types of people in the world, and those who know better."

Did I make that line up? (You won't break my heart if you can find a citation) Maybe I did THINK of it on my own (though not first) but out of curiosity I would love to know which smart, good-looking (and modest) folk came to it before me.

I consider myself a talented web searcher, but the cornucopia of "There are two types of people in the world..." quotes make it difficult for me to sift through the throngs.

Thanks!