About 40 students raise their hands.
'Has anyone here ever touched a ghost?'
'That's fantastic. Now let me ask you one question further. Have any of you ever made love to a ghost?'
Way in the back, Abdul raises his hand.
The professor takes off his glasses, and says 'Son, all the years I've been giving this lecture, no one has ever claimed to have made love to a ghost. You've got to come up here and tell us about your experience.'
The big plump boy from Helmand replied with a nod and a grin, and began to make his way up to the front podium.
When he reached the front of the room, the professor asks, 'So, Abdul, tell us what it's like to have sex with a ghost?'