An idea that at first seems like an amazing insight (at least to the conceiver) but later turns out to be pointless, mundane, stupid, or incorrect, and often is the root cause of bad decisions. Mostly occurs under the influence of drugs or alcohol.
Here is a bimutual epiphanot from one of Americas cinematic masterpieces, National Lampoon's "Animal House"...
Larry: Okay. That means that our whole solar system could be, like one tiny atom in the fingernail of some other giant being. (Jennings nods) This is too much! That means one tiny atom in my fingernail could be--I think I'll be using this word a lot with woos like Michael Egnor.
Jennings: Could be one little tiny universe.
Larry: Could I buy some pot from you?