The nuclear family (parents and children only) is a recent and relatively unusual family structure historically.

Mozart composed his first symphony at age 8 and had written over 600 works by the time he died at 35.

Chocolate was once used as currency by the ancient Aztecs.

About 80% of millionaires are self-made.

Chocolate was consumed as a bitter beverage by the Aztecs long before it was made into solid bars.

The Twitter bird's official name is Larry, named after Larry Bird of the Boston Celtics.

Rowing is considered one of the most physically demanding Olympic sports, requiring near-maximal effort for about 6 minutes.

The word 'punk' originally referred to a prostitute in Elizabethan England before evolving to its modern meanings.

Most people will earn over $1 million total during their lifetime.