The "aha moment" is also known as the eureka effect. Psychologists call this "insight problem solving", which is terrible for interviewing since like you said since it isn't a problem that you can build up towards solving. As a teacher, I try to make sure my assignments/quizzes don't fall victim of this.
For anyone interested, there are a lot of interesting studies on the topic if you search on Google Scholar. You've probably already seen matchstick arithmetic problems before (i.e., move a single matchstick to make the equation valid).
It never ceases to amaze me that a profession full of people that studied something called “computer science” is also filled with people that refuse to read the literature when it comes to hiring and instead lean on gut feelings, anecdotes, and cargo cult-ing.
I've researched a lot about this since I've had to do hiring, but I haven't been lucky enough to find anything collectively definitive or comprehensive enough to describe as "the literature." Most of it leans towards "what not to do," which is helpful but leaves some gaps. What do you recommend?
For anyone interested, there are a lot of interesting studies on the topic if you search on Google Scholar. You've probably already seen matchstick arithmetic problems before (i.e., move a single matchstick to make the equation valid).