A moment of clarity followed by the realization of just how shitty a given situation truly is. Commonly follows the act of undertaking a task, usually work related, and once fecal lucidity is achieved it is punctuated by the phrase "Oh, fuck!", "Fuck me!", or "Shitty shit shat!"
When Tim was assigned the task of recording company account spenditures he was elated but after going through expense reports and other financial records he had a moment of fecal lucidity, screamed "fuck me!", and ran to the closest bar to get blotto.
Clarity, especially mental clarity, that one is completely and totally wallowing in shit.
"I've been working on a project for my boss all week and last night I had a moment of fecal lucidity. There is no fucking way I will be able to complete it by the deadline because I have no clue what I am doing!" -Me