I had to explain to 2 teenage girls (15 and 16) that the reason the candle went out was because they put the glass lid back on it's jar. 1 of them said that fire can only be put out with water. I explained that fire needs oxygen and putting the lid back on it cut the supply. When they didnt understand after explaining a few times I had to explain it to them like toddlers. "Fire is hungry, so it eats the air. When all the air is gone, it goes to sleep. Bye bye fire." The double "ohhhh" was too much.

P.S. The look on their mama's face was so funny. She turned to me, threw her hands up, and said "I've failed." In the most defeated tone. That poor woman.

Edit: I would like to point out that we did, in fact, have a serious talk to these girls about proper fire safety, and when to NOT use water on an open fire.