A sudden, intuitive perception of or insight into the reality or essential meaning of something very basic, annoyingly obvious, or - in hindsight - really stupid. The person having the stupiphany is generally greatly excited, while observers just shake their heads at how obvious the answer was.
It dawned on Dan one morning as he was driving that the word windshield was made up of the 2 words describing what it did: "I've had a stupiphany!" he ejaculated!
Maria's latest stupiphany came when she looked up Men At Work lyrics and realized it was "a vegemite sandwich" instead of "a bite of my sandwich" in the song Land Down Under.
After several years of training/certification, Seth suddenly realized that CPR was really just manually activating the heart to pump blood: it was a real stupiphany.