Because

J.M. Barrie added the requirement of fairy dust for flying, because so many children injured themselves trying to fly after seeing the first production of “Peter Pan”

J.M. Barrie added the requirement of fairy dust for flying, because so many children injured themselves trying to fly after seeing the first production of “Peter Pan”

In 1999, NASA lost a $125 million Mars orbiter because half the project staff used imperial measurements and the other half used metric.

In 1999, NASA lost a $125 million Mars orbiter because half the project staff used imperial measurements and the other half used metric.

The revolving door was invented because the inventor disliked the social convention of men holding doors for women.

The revolving door was invented because the inventor disliked the social convention of men holding doors for women.