I found Jason Fried's analogy in "Rework" useful. Paraphrasing: "Going to work" is like going to sleep. If someone keeps interrupting you every few minutes, you're never going to fall asleep. It takes uninterrupted time to get there.
I've tried to use this analogy with my wife. Still working on it.
I've tried to use this analogy with my wife. Still working on it.