In S01E08 of Silicon Valley, during a certain scene about phallic physics, the founder of Pied Piper
suddenly has an epiphany about "middle-out compression", leading to the revolutionary compression algorithm that ends up saving their arses and getting them funded.
Have you ever had a groundbreaking idea come to you like an epiphany, all at once - as opposed to gradually through deliberate brainstorming - that solved a major technical problem for you, and what was it?
Monotonous physical movement is an epiphany trigger. Activities like running, washing dishes, and showering all set the stage for the epiphany to arrive. It can take a week or two when it comes. If it doesn't then I take a break for a month and try again.