Capturing Thoughts

I once came across an interesting essay regarding the importance of writing down thoughts. It has been a couple of years, I don't remember all the good details very clearly so please take the following snippet with a grain of salt:

Thoughts are just fluffy things in our heads. Like clouds, sometimes few at a time, other times many at once, often times unclear and mixed together. The head can be a very noisy place. It is not until we write our thoughts down, essentially capturing them that they finally become realized as our thoughts.