In 1969, John Adair wrote the book, Training for Decisions, which had a problem involving connecting a box made up of nine dots with just four lines. The solution to this problem coined the phrase, "Thinking outside the box."
I love to solve problems. That's one reason I got into computer programming. This book helped shine light on a bad habit I have with problem solving. I try to solve the problem before I understand it. The book gave practical steps towards understanding a problem, but it warns about Information Overload. There's a fine line between "He who hesitates is lost," and "Look before you leap."
This book confirmed my belief in Hammock Driven Development. It's the idea that we need to sleep on complex problems. Doing this gives our "Depth Mind" or subconscious a chance to solve it. When you get stuck, let it go. "A problem is a solution in disguise."