It's when someone famous dies all the fake fans come out and say they cared so much about the dead person but everyone knows they didn't. Also when you see someone wearing a shirt of the dead person only after they died and wouldn't have it if the person was still alive.
Idiot: OMG I cant believe that persons dead, I loved all of their work and it was soo inspiring.
Guy: bull shit you did, you just have Dead Celebrity Syndrome (DCS). How did you feel about that person last week.