Hi there, it's Matt here and welcome back to the show. This one, it's an interesting one.

Pre-Cognitive Dreams.

If you watch enough late night TV, which this is a sleep podcast, I already hope you're not watching late night TV,

unless you're a night out.

No judgment there.

If you're watching that kind of television or if someone else is watching that kind of

television, there is always the story of a very well documented case of someone very clearly

predicting in their dream at night something that later happens in the future, and it is with such precision

that it makes it seem absolutely irrefutable. In other words they were having a pre-cognitive dream, a predictive dream.

Sadly what I've just described is, alas, very much non-sensical statistical chance.

Allow me to explain. There are around 8 billion people in the world at this moment.

And across a night each one of us may have four or five REM cycles.

So let's do a little bit of back of the napkin mathematics here, and I'm going to be really conservative to try to give this hypothesis of

Pre-Cognitive dreaming the very best shot it has at being true.

So let's assume that we only have one dream per REM sleep cycle. Now that's

probably untrue. And then also let's assume that we only dream in REM sleep, which

we also know that you have dreams in other stages of sleep, but let's just be really

conservative here. And then let's also be clear that perhaps not all

people sleep long or sleep very well that night. So if we do the mathematics, 8 billion

people, maybe 5 REM cycles per night and just one dream for each

of those 5 REM cycles.

Rather than saying that there are perhaps 40 billion dreams that happen each

...