Write a few lines about your day once a week. A year later, you’ll be able to read yourself growing up.

Memory edits as it stores. A year later you will recall the big events and the shape you have since given them, not what you actually thought at the time, and the gradual change in you will be invisible with no earlier version to compare against. Notes written at the time do not get revised. That is their entire value.

Three lines on a Sunday is enough: what happened, what you were worried about, what you wanted. Keep them in one file. When you do, the thing you will notice is not the events but how differently the person writing them thinks.