A phrase used in response to someone starting a new thread/conversation/tweet/etc... about a topic/website/video/etc... that was discussed ad nauseum by the rest of the civilized
world a number of months/years ago.
The phrase is derived from the Back to the
Future trilogy of movies which involved a DeLorean that could travel through
time. The plot of the first movie in the trilogy revolves around the main character becoming trapped in the past when he can'
t refuel the DeLorean.