While an average human body has 10 trillion cells, the bacteria in your gut (flora) is on the order of 100 trillion. When you're born, there is no gut flora in your digestive tract and the very first poop you ever take as a human being is said to be essentially sterile, known as "meconium".
Contagious yawning is thought to be a sign of empathy. You're most likely to experience contagious yawning with people in the following order: family, friends, acquaintances and lastly strangers.
Adolph Hitler led the first public anti-smoking campaign in modern history. Here is another one. "Adolf Schicklgruber" would have been Hitler's name if his father had not changed his last name in 1877.
In some 19th century cities, poor children worked as crossing sweepers cleaning roads of horse manure in order for the rich to cross the street
