One thing is common for all boring lectures: sleeping students.
Related posts:
Romantic wedding cake
Shooting the cheater
Before and after girl
Recycle bin for bottles
Barber services as usual during flooding
Funny US town name: Cookietown
Funny high heel for feminists
Hairdo for hardcore football fan
Funny squirrel--only seen in Australia
Dog king and cat queen
Funny monkey touching the breast
Girl sleeping with two dogs