Adolescent

The teacher had just finished reading a story to the sixth-grade class.
She decided to check the student's knowledge of some of the vocabulary that had been used.
- Who knows what the word "adolescent" means ? she asked.
Out of the entire class of 33, not one child raised a hand.
After a few more silent moments, she decided to give them a hint :
- Adolescent - it's something all of you are, and I am not.
Finally Little Johnny tentatively raised his hand, and in a very soft voice said :
- Virgins ?