Dementors are the guards of the wizard prison of Azkaban. Their origin is unknown, and it is also unclear how anyone reached agreement with them to carry out this role, as they are speechless, sightless and psychopathic. They feed on positive human emotions – happiness, hope, excitement. Their mere presence sucks every happy feeling or memory from any human present, leaving only cold dark despair in its place. The worst experiences of the victim’s life will flood through them as everything positive is stripped away. This effect causes the vast majority of Azkaban inmates to go insane in a very short length of time. Any wizard exposed to a Dementor for long enough is also likely to lose their powers. –Dementors were created by J.K. Rowling in The Prisoner of Azkaban, but I don’t remember whence I lifted this description (sorry)

I met a dementor on a carpool—someone who was so negative, unhappy, nothing-is-my-fault, self-absorbed, and whining that it sucked my own good mood right out of me. I had to take desperate measures to withdraw from further carpooling. 

I waited a very, very long time before posting this, so that the Dementor of the gig wouldn’t recognize him- or herself if s/he chanced upon this blog around the time of the gig.