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Those plastic or metal tips on both ends of your shoelaces are called aglets, and they're more important than you'd think. Just try lacing a shoe without them. In fact, aglets have been around since ancient Rome, though they were usually made out of stone or glass at that time. The word "aglet" comes from the old French aiguillette, meaning needle. Who knew so much thought and history went into keeping your shoelaces from unraveling?

Many countries use coins for their equivalent of one dollar because paper money wears out so quickly. U.S. dollar bills—the most circulated denomination of bill—only last an average of a year-and-a-half before they need to be taken out of circulation and replaced. In fact, though the U.S. Mint prints about $696 million (or 37 million bills) a day, 95 percent of that simply goes out to replace bills that are faded, torn, dirty, or otherwise unsuitable to be circulated

A Swedish mathematician recently calculated the number of different ways to tie a tie at over 175,000. This is especially shocking considering that a previous study set the number firmly at 85—quite a difference. The newer study took into consideration many variants which the previous one did not, including exposed knots, wrappings, and windings. They even created a knot generator to show you a variation (and how to tie it) at random. Still, despite this sartorial discovery, if you take it from us, there's really only one proper way to tie a tie.

Though many think of them as the quintessentially French baked good, the croissant originated in Vienna, Austria, as early as the 13th century. Back then, it was a denser pastry known as a kipferl, but it was made in a distinctive crescent shape. There are many apocryphal tales of how the croissant made its way to France, but the first documented appearance of the modern croissant—now made with flaky, buttery puff pastry—didn't occur until the early 1800s, when a Viennese baker began selling his crescent-shaped creations in Paris.

Have you ever taken a close look at your computer's keyboard and wondered why the letters seemed to be randomly strewn across the keys? In reality, it's not random at all. This QWERTY design (named for the top left row of letters) was invented in 1872 for the typewriters of the time. Typists were getting faster than the machines they used, which would cause the typewriters to jam, so slowing them down actually saved time in the long run. There's no need for the same result now, but everybody's so used to QWERTY keyboards that they've even made the leap to smartphones.

In 1957, two engineers came up with the idea to glue two shower curtains together, trapping tiny bubbles of air in between them. They were trying to come up with a type of textured wallpaper, but it didn't take off. Then they marketed their creation as greenhouse insulation, but again, it went nowhere. Finally, in 1960, IBM needed to ship some delicate data processors, and a phenomenon was born. The beloved tradition of popping the individual bubbles might even have mental health benefits—a recent study showed that one minute of popping Bubble Wrap was as relaxing as a 30-minute massage.

Forest Mars, son of the candy company's founder, developed a method of manufacturing drops of chocolate inside a hard candy shell and set up shop in New Jersey in 1941. He then approached a friend about going into business together: Bruce Murrie… son of the founder of Hershey's. For the first few years, M&M's contained Hershey's chocolate, but alas, the two men had a falling out in 1949 and Mars bought back his share of the company. The partnership may have only lasted eight years, but the two candy barons are immortalized together in this ever-popular snack's name.

Barbie's been around since March 9, 1959, when she was unveiled at the New York Toy Fair. Her creator, Ruth Handler, based her image on a German doll that was a favorite plaything of her daughter, Barbara. Barbie's very first look was a black-and-white striped swimsuit, with hair pulled into a fashionable ponytail, and since then, she's served as an inspiration for numerous artists and fashion designers worldwide.

In the United States, roundabouts are rare enough that drivers often become confused or frustrated upon encountering them. However, they're more common in Europe because they promote safety. A four-way intersection offers 56 potential points of conflict—that is, chances for you to hit a pedestrian or another car. A roundabout reduces that number to 16. They do require drivers to slow down, but since a traffic light requires stopping on red a large portion of the time, roundabouts actually allow for faster travel, as well.

If you've got a spaghetti spoon—that's the one with the large tines for separating strands of pasta—take a look at it. Does it have a single, circular hole in the middle? You might assume that's to drain off water when you lift the cooked spaghetti from the pot, but it's even more specific than that. The amount of dry spaghetti that fits through that hole is a single serving. No more guessing about how many noodles you need!