I updated “Created Serendipity: Chance Favors the Connected Mind” with selections from “Rabbit holes: Why being smart hurts your productivity : Sridatta Thatipamala”.
Richard Hamming puts it yet another way in his essay You and Your Research:
I notice that if you have the door to your office closed, you get more work done today and tomorrow, and you are more productive than most. But 10 years later somehow you don’t know quite know what problems are worth working on … He who works with the door open gets all kinds of interruptions, but he also occasionally gets clues as to what the world is and what might be important. … [T]here is a pretty good correlation between those who work with the doors open and those who ultimately do important things, although people who work with doors closed often work harder.
What both of them are saying is that producing brilliant work is heavily reliant on serendipity. Putting your nose to the grindstone will certainly get things done, but when you are working on cutting-edge problems with no predetermined path to success you derive inspiration through chance discoveries.
Both these men were probably relied on conversations with their brilliant colleagues to deliver them random insights. But they also had the advantage of working at the top of their games at Caltech  and Bell Labs, respectively. The common geek today relies on the Internet, especially community watering holes like HackerNews and Reddit, to keep abreast of “what the world is and what might be important”.