“Today when you say “nest egg” many think of money saved and put away, but a literal “nest egg” is a real or fake egg that you put in a nest to encourage a bird or a hen to lay more eggs there. So what Thoreau is saying is that by simply writing down a thought, you encourage more thoughts to come. When you have enough thoughts pushed together in the same space — a collage of thoughts, juxtaposed — they often lead to something totally new.
“This is the magic of writing.”
Whoa.