It started when a staffer at Buzzfeed, R.I.P. wrote, this is important because I think I'm going insane.

Someone had sent her a picture of a party dress and said,

Please help. I posted a picture of a dress, or some people are seeing

as blue and black and some people are seeing it as white and gold. Like, can you explain

we're losing it? We, rhetorically ask, is the sky blue?

When the answer is, of course, we never think

someone's gonna say it's green.

But here, people of good faith and fine vision

saw different things.

That picture went viral, and then that picture came to define viral. Nine years later, it still fascinates us.

I'm not a textile reporter nor obsessed with fashion, but I have been extremely interested in human perception and our blind spots

and how our brains make decisions about what we're seeing and they don't tell us how much they're guessing.

As we'll hear, that moment of virality was a turning point.

Coming up on today explained, the last best day on the internet.

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