Evolution

A child asked his father, "How were people born?" So his father said, "Adam and Eve made babies, then their babies became adults and made babies, and so on." The child then went to his mother, asked her the same question and she told him, "We share a common ancestor with monkeys and we evolved to become like we are now." The child ran back to his father and said, "You lied to me!" His father replied, "No, your mom was talking about her side of the family."

New Millennium

Recently, on an outing with my scout troop, the question came up of whether the new millennium began January 1st, 2000, or 2001.
The Scoutmaster explained that each century begins with year "1" and ends with year "100" —  the 20th century began at the start of 1901 and ended at the close of 2000.
To illustrate his point, the Scoutmaster gathered 15 berries and asked the boys how many he had. Each boy correctly answered "15".  
"Now which berry is number '0'?" He asked next, to which one boy blurted out:
"The one that isn't there!"

Pliers

"They're multipurpose. Not only do they put the clips on, but they take them off." -- Pratt & Whitney spokesperson explaining why the company charged the Air Force nearly $1000 for an ordinary pair of pliers.