Hey, brain stuff, I'm Christian Sager here to tell you why Friday is considered unlikely because in North America and Europe, a significant proportion of the population behaves very strangely on Friday.

Some people won't fly in airplanes, host parties, apply for jobs, get married, or even start new projects.

In fact, in the United States, roughly eight percent of the population is afraid of Friday, which is a condition known as and say it with me here paraskeva deca tree a phobia.

That's right, it's actually a combination of two separate fears.

We have a fear of the number thirteen that's called triscadecaphobia, and a fear of Friday's Anyways, the most familiar source of both of these phobias is actually Christian theology.

Thirteen is significant to Christians because it is the number of people who were present at the last sub birth.

Because you've got Jesus and his twelve apostles, and then Judas, the apostle who betrayed Jesus, was allegedly the thirteenth member of the party to arrive.

Maybe Judas was just being fashionably late, but Christians have traditionally been wary of Fridays because they also think that Jesus was crucified on a Friday.

And some theologians think that Adam and Eve eight from the forbidden Fruit on a Friday.

So what's going on here?

Why are all the worst events in the Bible happening on Friday, including the Great Flood?

Yes, supposedly Noah and his arc also set sail on a Friday as Friday, God's least favorite day.

Because of all of this, in the past, many Christians would never begin any new project or trip on a Friday, for fear that the endeavor would be doomed from the start.

Now, sailors were particularly superstitious in this regard, often refusing to ship out to sea on a Friday.

But according to nautical legend, in the eighteenth century, the British Navy commissioned a ship called the Hmis Friday.

In order to quell the superstition.

The navy selected the crew on a Friday, they launched the ship on a Friday.

They even selected a man named James Friday as the ship's captain, and then one Friday morning that ship set sail, but as bad luck would have it, it disappeared.

Now, some historians also think they can trace Christian distrust of Friday to the Church's overall opposition to pagan religions, because did you know this Friday is named after Frigg, the Norris goddess of love and sex, and now this strong female figure, these historians claim, posed a threat to the male dominated Christianity.

So to fight her influence, the Christian Church characterized her as a witch, vilifying the day after her.

This characterization may have also played a part of the fear of the number thirteen trisca decaphobia.

Remember that word I did and now I can say it correctly.

It was said that frig would often join a convent of witches, normally a group of twelve, bringing the total number to thirteen, and a similar Christian tradition holds that thirteen is unholy because it signifies the gathering of twelve witches and the devil.

Some trace the infamy of the number thirteen also back to ancient Norris culture.

In Norris mythology, the beloved hero Balder was killed at a banquet by the malevolent god Loki.

You know Tom Hittleston who crashed the party of you guessed it?

Twelve people bringing the group to thirteen, and this story, plus the story of the Last Supper, led to one of the most entrenched connotations of the number thirteen.

You should never sit down to a meal at a group of thirteen.

Another significant part of the Friday the thirteenth legend is particularly bad in This was a Friday the thirteenth that occurred in the Middle Ages.

On a Friday in thirteen o six, King Philip of France burned the revered nights of Templar at the stake, marking the day as an occasion of evil.

Now these days, some people come to fear Friday because of misfortune they've experienced on that day in the past.

So if you get in a car wreck on Friday the thirteenth or lose your wallet on that day, then that superstition is bound to stick with you if you think about it.

Though terrible things horrible things are just mundane things like spilling coffee on your lap, or losing your wallet or losing your cell phone.

This stuff happens all the time, but if you're looking bad luck on Friday, you'll probably find it.

Jason Borhes check out the Brainsuff channel on YouTube and for more on this, and thousands of other topics.

Visit how stuff works dot com.