Sudden realization that your epiphany wasn't that significant.
Mary shouted "Eureka!" and then realized her mistake. Yet another fauxpiphany in a long career of failure...
A fauxpiphany is a sudden and surprising realization into the meaning of something, only to realize moments later that, alas, you were all wrong. Term coined by the great Lauren Brenner.
"Like a flash, it came to me why Pedro is always acting in that loud and unpredictable way...he is a genius savant!
But it was a fauxpiphany. Pedro is just an asshole."