Sometimes you just don't feel like it. When you think about how much time you might really have left on this planet and be faced with the stark realization that you'll be spending most of it in traffic, cubed into cubicles, following someone else into the breech in an effort to be a good team player so as improve the company's bottom line and hope that sound you hear is not your arteries hardening...then it's time to let off some steam. Since going postal has permanent consequences then you might try watching these on some personal net surfing time at work.
Low Morale is a series of animations portraying one man's struggle to cope with the soul-sapping, will-to-live draining, life-force mugging, morale crushing experiences of work. Any correlation between events showed and real-life have been personally researched.
Check out the Radiohead acoustic version of "Creep" lip-synched to enjoyable lenghts.