A Lecture

A cop stops a drunk guy at 4 AM.
"Where are you going, ser?"
"To a lecture." - says the drunk.
"Really? And who gives lectures at at this time of night!?"

"My wife."

Ahahah! You see, in this joke we expect the policeman to somehow end up less smart then a drunk, and in the end he does and we are glad. The expected doesn't makes us laugh here, but the UNEXPECTED way a drunk is smarter then the cop. Statisticaly, people who received a hit with a policeman stick tend to laugh to this joke a tiny bit more then others.