A German teenage boy was upstairs playing on his computer when his grandad came in the room and sat down on the bed.
"What are you doing?" asked the grandad. "You're 18 years old and wasting your life! When I was 18 I went to Paris, I went to the Moulin Rouge, drank all night, had my way with the dancers, pissed on the barman and left without paying! Now that is how to have a good time!"
A week later, the grandfather comes to visit again. He finds the boy still in his room, but with a broken arm in plaster, two black eyes and missing all his front teeth.
"What happened?" he asked.
"Oh Grandfather! " replied the boy. "I did what you did! I went to Paris, went to the Moulin Rouge, drank all night, had my way with the dancers, pissed all over the barman, and they beat the crap out of me!"
"Oh dear!" replied Grandpa. "Who did you go with?"
"Just some friends. Why? Who did you go with?"
"Oh!" replied Grandpa. "The German army!"