Pop Rocks and Soda
No, in fact you will not explode if you eat Pop Rocks and drink quantities of soda. It was a myth that people thought that. There is simply not enough carbon dioxide produced.
Another myth popular at that time was that a car equipped with rockets would reach a speed of about 300 miles and hour and become airborne. tests were done to determine how realistic that is and they were unable to reach 300 miles per hour and the car did not get airborne.
Still it is interesting.