Two young men are arrested for drug offences. When they appear in court, the magistrate takes a liking to them and says, "You two seem like decent young men, so I'd like to give you a second chance. I want you to go out this weekend and try to show others the evils of drug use and to get them give up drugs. I'll see you back in court on Monday morning." Come Monday morning the two lads are in court and the magistrate says to the first one, "So, how did you do over the weekend?" "Well your honour," he replies. "I managed to persuade 17 people to give up drugs." "Seventeen people?" says the magistrate. "That's wonderful news. How did you achieve that?" "Well your honour," he replies. "I drew two circles like this: O o and told them that the big circle was your brain before drugs, and the small circle was the brain after drugs." "That's admirable," said the magistrate. "And how did you do?" he asked the second one. "Well your honour I peruaded 156 people to give up drugs." "One-hundred and fifty-six people!" cried the magistrate. "That's amazing! How did you manage that?" "Well, I used the same two circles. I pointed to the small circle and told them, this is your arsehole before you go to prison. Then I pointed to the large circle and told them this is your arsehole after 6 months in prison."