[EdwardCoffin]

I've been keeping a journal for about 12 years. It's in simple text files, one per day, one directory per year. It mostly contains health-related information: what I ate, any reactions to what I ate (I have various food allergies and such), any exercise I did, how much I weighed. It also contains mention of significant events, like when I finish a book, any movies I might have watched, friends I met up with, things like that.

It has mostly been useful for occasional reference. It is useful to notice long-term health trends and patterns. It is also useful to be able to confirm suspicions like whether I might have got an idea from a book I read - did I read it before or after some idea I had say six years ago.

Things I have found useful in writing the journal are to make sure things are spelled correctly, so I can easily grep through it without worrying about whether I made a typo. Ditto regarding synonyms: I strive to use the most common word to describe something and not get fancy. I use conventions for recording things, so for example my weight is on its own line in the format "Weight: xxx", so it is easy to write scripts that scrape such information to build tables and graphs.

There is very little beyond strict factual information, and I write it in prose, not bullet-form.