One speaker
Alexander von Humboldt (1769-1859), the great German explorer, naturalist and geographer was something of a one-off himself (he is often referred to as the "last man who knew everything").
In his epic South American journey of 1799-1804, he came across an elderly parrot that was the sole speaker of an extinct Venezuelan language. Humboldt recorded the last 40 words of the Arture indians direct from the parrot's mouth.
One signature
Michelangelo only signed one sculpture: The Pietà, completed in 1500. He was prompted to do so by an overheard conversation in which his masterpiece was attributed to another sculptor.
He sneaked into the chapel where the statue was placed and, by candlelight, carved: Michaelangelus Bonarotus Florentinus Faciebat ("Michelangelo Buonarotti, Florentine, made this").
He later regretted this chiselled outburst and never signed a work again. In the 1970s, a crazed artist named Lazlo Toth attacked The Pietà with a hammer, screeching: "I am Jesus Christ, risen from the dead!" Restorers working on the damage found a secret "M" monogram by Michelangelo carved into the marble lines on the palm of Mary's left hand.
One eye
The Cyclops legend may have its origin in elephant skulls. Two million years ago, elephants were widespread across what is now the Mediterranean, particularly on islands such as Sicily and Crete.
When the Greeks arrived there 5,000 years ago, they would almost certainly have uncovered the fossil remains. Elephant skulls, without the trunk or giveaway big ears, do look rather like the remains of a one-eyed giant.
The huge central nasal cavity, from which the trunk hangs, looks like a socket for a single large eye. The actual eye sockets are very small and on the side of the head.
One daffodil
Prince Charles is paid one daffodil annually by the Isles of Scilly Wildlife Trust as rent for all the empty land, islands and rocks within the isles.
One birthday
Yin Yat, the 7th Day of Chinese New Year, is known as "Everybody's Birthday", when all Chinese add a year to their age. In Chinese tradition, all humans were created on the 7th day, dogs on the 3rd and crops on the 8th.
Thoroughbred horses worldwide share January 1 as their official birthday. Breeders try to foal their horses close to the start of January, to ensure they are as mature and strong as possible for their year-group.
One food
Properly stored, honey is the one food that does not spoil - 3,000-year-old honey found in the tombs of Egyptian pharaohs was tasted and considered edible. Honey is hygroscopic: it can absorb and hold moisture so that any moulds and bacteria that touch it quickly lose their own moisture and die.
It's why cakes made with honey stay moist longer than ones made with sugar.
