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.
Austin Kleon wrapped up a recent post with the quote above. The post on one level is about journaling and writing in general, but do you know what else that quote describes? A blog.
A blog is nothing more than a series of thoughts written down over a period of time. When you think about it that way it’s incredibly freeing. There should be no pressure. Instead there should just be turning up to write down a thought and seeing where it takes you.