When this notion first drifted into my mind, it was meant to be silly and sarcastic. Yet, the more I think about it, the more striking it becomes. Most informal definitions of "normal" invoke an unconscious selection, a small statistically erroneous sample of society. Generally, this is the subculture which one interacts with. "Normal" is devoid of diversity.
Now, consider, what might be considered normal at broad, even global levels. Language, idiom, norms and behaviors at a planetary level wouldn't reflect the norms of US culture, or even Western culture. Probably some blend of Chinese and/or South American culture, if such a thing exists.
Perhaps we shouldn't get quite so wrapped up in being normal. Or, more importantly, judging those who aren't normal. I've always delighted in the weird, those people who experience the world uniquely, and are filled with confidence about their glorious difference. Brings to mind one of my favorite Kerouac quotes (On The Road): “the only people for me are the mad ones, the ones who are mad to live, mad to talk, mad to be saved, desirous of everything at the same time, the ones who never yawn or say a commonplace thing, but burn, burn, burn like fabulous yellow roman candles exploding like spiders across the stars.” Me too, Jack. Me too.