As it has a wordcount feature, I can tell you exactly how long it is: 1,067,605 words long! I've never missed a day. (It's actually quite easy to keep, five or ten minutes here and there at a computer.)
I've chronicled jury service, surgery, funerals, weddings, the abortion referendum, pro-life marches, major storms, Brexit, Donald Trump's election, a visit to a radio studio, several visits to television studios, and lots of other stuff.
I have a complete record of writing my book, from the moment of inspiration (when I was praying the rosary on my morning bus) to the moment I held it in my hand for the first time.
I know pretty much everything I ate for breakfast, lunch and dinner for the last three years!
I record my dreams, when I remember them. I record interesting conversations. I record amusing or memorable incidents I witness on the street or bus or elsewhere. I take notes of the homilies I hear at church. Sometimes I even record little things like a change of shelf layout in the supermarket.
Will anyone ever read it? Well, I will read it, if nobody else does.
It's also a diary of my inner life, as well as my outer life. I record my dreams (when I remember them), my ideas, my fascinations, my internal debates, my reactions to whatever I'm reading. These are especially interesting to re-read. My diary flows into my other writing.
This was the first paragraph I wrote, this day three years ago. (The teen diary mentioned covered less than a year.)
I decided yesterday-- or was it today?-- that I would start keeping a diary again. Strangely enough, it was the memory of a passage in Brideshead Revisited that did it. There is one section set aboard a liner that filled me with a strange fascination with the notion of days, of how our lives are divided into these units. And I remembered, from the computer diary I kept in my teens, how delicious the in-betweeny days seemed to be-- the uneventful, reflective days-- and how each day seemed to have more of an identity when it was preserved in a diary. Even though that diary is long lost, I remember the days I chronicled in it as days because I chronicled them. Hence-- this.
Keep a diary! You'll be glad you did!