Why do men's clothes have buttons on the right while women's clothes have buttons on the left?
When buttons were invented, they were very expensive and worn primarily by the rich. Since most people are right-handed, it is easier to push buttons on the right through holes on the left. Because wealthy women were dressed by maids, dressmakers put the buttons on the maid's right! And that's where women's buttons have remained since.

Why do ships and aircraft use 'mayday' as their call for help?
This comes from the French word m'aidez - meaning 'help me' -- and is pronounced, approximately, 'mayday'.

Why are zero scores in tennis called 'love'?
In France, where tennis became popular, round zero on the scoreboard looked like an egg and was called 'l'oeuf,' which is French for 'egg.' When tennis was introduced in the US , Americans (mis)pronounced it 'love'.

Why do X's at the end of a letter signify kisses?
In the Middle Ages, when many people were unable to read or write, documents were often signed using an X. Kissing the X represented an oath to fulfill obligations specified in the document. The X and the kiss eventually became synonymous.

Why is shifting responsibility to someone else called 'passing the buck'?
In card games, it was once customary to pass an item, called a buck, from player to player to indicate whose turn it was to deal. If a player did not wish to assume the responsibility of dealing, he would 'pass the buck' to the next player.

Why do people clink their glasses before drinking a toast?
It used to be common for someone to try to kill an enemy by offering him a poisoned drink. To prove to a guest that a drink was safe, it became customary for a guest to pour a small amount of his drink into the glass of the host. Both men would drink it simultaneously. When a guest trusted his host, he would only touch or clink the host's glass with his own.

Why are people in the public eye said to be 'in the limelight'?
Invented in 1825, limelight was used in lighthouses and theatres by burning a cylinder of lime which produced a brilliant light. In the theatre, a performer 'in the limelight' was the centre of attention.

Why is someone who is feeling great 'on cloud nine'?
Types of clouds are numbered according to the altitudes they attain, with nine being the highest cloud. If someone is said to be on cloud nine, that person is floating well above worldly cares.

Why are many coin banks shaped like pigs?
Long ago, dishes and cookware in Europe were made of a dense orange clay called 'pygg'. When people saved coins in jars made of this clay, the jars became known as 'pygg banks.' When an English potter misunderstood the word, he made a container that resembled a pig. And it caught on.

Did you ever wonder why dimes, quarters and half dollars have notches (milling), while pennies and nickels do not?
The US Mint began putting notches on the edges of coins containing gold and silver to discourage holders from shaving off small quantities of the precious metals. Dimes, quarters and half dollars are notched because they used to contain silver. Pennies and nickels aren't notched because the metals they contain are not valuable enough to shave.

Why is the Fire Engine Red?
The fire Engine extinguishes the fire.
Fire is caused by wood.
Woods comes from trees.
Trees are in the jungle.
Jungle has lakes.
Lakes have fish.
Fish have fins.
Finns are the neighbors of Russia,
Russian flag is red -- That is why the fire engine is red!

Why the US Railroad Gauge is 4' 8.5"
Here's a look into the corporate mind that is very interesting, educational, historical, completely true, and hysterical all at the same time.

The US standard railroad gauge (distance between the rails) is 4 feet, 8.5 inches. That's an exceedingly odd number. Why was that gauge used? Because that's the way they built them in England, and English expatriates designed the US railroads.

Why did the English build them like that? Because the first rail lines were built by the same people who built the pre-railroad tramways, and that's the gauge they used.

Why did 'they' use that gauge then? Because the people who built the tramways used the same jigs and tools that they had used for building wagons, which used that wheel spacing.

Why did the wagons have that particular odd wheel spacing? Well, if they tried to use any other spacing, the wagon wheels would break on some of the old, long distance roads in England, because that's the spacing of the wheel ruts.

So who built those old rutted roads? Imperial Rome built the first long distance roads in Europe (including England) for their legions. Those roads have been used ever since.

And the ruts in the roads? Roman war chariots formed the initial ruts, which everyone else had to match for fear of destroying their wagon wheels.

Since the chariots were made for Imperial Rome, they were all alike in the matter of wheel spacing.
Therefore the United States standard railroad gauge of 4 feet, 8.5 inches is derived from the original specifications for an Imperial Roman war chariot.

So the next time you are handed a specification/ procedure/ process and wonder 'What horse's ass came up with this?' you may be exactly right. Imperial Roman army chariots were made just wide enough to accommodate the rear ends of two war horses.

AND The Space Shuttle's Design?
Now, the twist to the story:

When you see a Space Shuttle sitting on its launch pad, there are two big booster rockets attached to the sides of the main fuel tank. These are solid rocket boosters, or SRBs. The SRBs are made by Thiokol at their factory in Utah.

The engineers who designed the SRBs had preferred to make them a bit fatter, but the SRBs had to be shipped by train from the factory to the launch site. The railroad line from the factory happens to run through a tunnel in the mountains, and the SRBs had to fit through that tunnel. The tunnel is slightly wider than the railroad track, and the railroad track, as you now know, is about as wide as two horses' behinds.

So, imagine a major Space Shuttle design feature of what is arguably the world's most advanced transportation system was determined over 2,000 years ago by the width of a horse's rear.
So the ancient horse's rear ends controlled almost everything.....