Two guys are working a long shift in a warehouse when suddenly one strips off his clothes, climbs to the rafters and swings from one of the lights. The boss comes over and asks him what he's doing, to which the guy replies "I'm a lightbulb!"
The boss scratches he head and says "Boy, you've been working too hard, why don't you come down and take the rest of the day off?"
The guy scampers down, puts his clothes back on and leaves. His buddy starts to follow when the boss stops him. "Just where do you think you're going?" he asks.
"You don't expect me to work in the dark do you?" is the reply.

having myself worked until 3am yesterday and back in today at 6am, I can totally understand how this is completely possible...

I was totally hallucinating when I 'woke up' today 

Cheers