Journaling generates value from introspection and retrospection
Journaling generates value in two ways:
You gain introspective value through looking inward and exploring yourself while writing the journal entry. Not every day will generate this, but if you participate in the process then most days can be this way.
You gain retrospective value when you revisit those journal entries at a later date. I do this through Weekly Reflection and by Revisiting the journal entry from this day one year ago