Keeping a plain-text logbook
For a little over three years I have kept a logbook in a plain text file. One file per year, named after the year, one line per entry. Each line starts with the date and the time, then whatever happened. That is the whole system.
It began after a bad week at work. Somebody asked when we had last changed a particular setting, and I was sure I knew, and I was wrong by about two months. Nothing broke because of it, but I remember the feeling of reaching for a memory and finding a guess in its place. That evening I opened an empty file and wrote down the three things I had done that day. The next morning I did it again.
The rules I ended up with are few. Write the line when the thing happens, not at the end of the day, because at the end of the day you remember the version of events you would have preferred. Keep it short; a line that needs a paragraph is a sign that the paragraph belongs somewhere else, with a pointer from the log. Never edit old lines. If I got something wrong, I add a new line that says so. The file is allowed to be embarrassing.
A typical stretch looks like this:
2025-03-11 09:12 started on the import job, old one still running 2025-03-11 11:40 import job: the slow part is the date parsing, not the disk 2025-03-11 16:05 dentist moved to Thursday 2025-03-12 08:55 import job: rewrote the parser, 40 min down to 6
Work and life share the file. I tried keeping them apart for a while and it made both halves worse. Half of the useful questions I ask the log are about context: what else was going on the week a decision got made, whether I was tired, whether I had just come back from a trip. A separate work log cannot answer that.
What has it actually been good for? Mostly the boring questions. When did I last renew this, how long did that take the first time, which week did the noise from the flat upstairs start. I search it with grep and nothing else. Once a year, usually in the quiet days at the end of December, I read the whole file from the top. That is the part I did not expect to enjoy. It is a strange, flat kind of diary, all verbs and nouns, and it is far more honest than anything I would write if I sat down to reflect.
I have been asked why I do not use one of the many applications built for this. The honest answer is that I have outlived several of them. A text file has no account, no export button and no company behind it that can lose interest. It opens in whatever editor is nearest, on any machine I will ever own, and in twenty years it will still open.
The only real cost is the habit itself. Some weeks the log is thin and I can tell, reading it later, that I was not paying attention. That turns out to be useful information too.