The disappointment of Apocalyptic thinkers

The disappointment of of Apocalyptic thinkers is in their prevailing sense that they have been let down, this doom laden thinking has been going on since 2nd Century AD and probably for a long time before that...till we come to the modern day version of the old geyzer witth his sandwich board
and his message repent for the the end is nigh, even Isaac Newton he of the great brain fell for this one, claiming that our end will come in 2060...