I have kept journals nearly all of my adult life. (That adds up to quite a few years.) I have also taught classes on journaling. I have often said that even if I were not a professional writer/author (which I am), I would still journal.
I find it so fascinating to re-read my journal on the first day of each new year. So many events I would have forgotten had I not chronicled them in my journal.
And by the way, I never buy the expensive journal-books. I simply use a spiral notebook. On the front I place a label noting the beginning date. Once the notebook is filled, I add the ending date. And that's it! So simple. So inexpensive!
Thank you @quitepoetic for sharing. I enjoyed your insight.