Bad Pop Rocks
Cassie was taking two of her grandsons on their very first train ride from Dayton, Ohio to Washington, DC.
A vendor came down the corridor selling Pop Rocks, something neither had ever seen before.
Cassie bought each one a bag.
The first one eagerly tore open the bag and popped one into his mouth just as the train went into a tunnel.
When the train emerged from the tunnel, he looked across to his brother and said: "I wouldn't eat that if I were you."
"Why not?" replied the curious brother
"I took one bite and went blind for half a minute."