Putting things down on paper always helps. It is different when the thought or idea "lives in your head."

When Abraham Lincoln was studying the law, in his early days, he used to read the text out loud, because he felt that adding the sense of hearing to the concentration work, accented his ability to retain material.

Putting things on paper allows you to "witness" if you will, your own thought process, have a look at your thinking, almost from outside yourself.

So, yes, I think it is enormously helpful.

If folks want, you can Google around. Some places offer courses in Journal Writing, or Memoir Writing...