Sometimes the writing itself is useful, like when I realise that I've been stressing about something minor for a few days, or when I hesitate to write down how I _really_ feel about something. In other cases it forces me to actually understand what I'm feeling in order to put it into words. In a sense those notes could be write-only and still be useful.

In other cases these notes are a complement to my photos. They show a different aspect of my life at a given moment. My photos don't show that on September 4, 2015, I had a massive crush on someone. I have built a timeline that combines my journals, photos, sketches, geolocation, Google searches and other things. It reveals a far more nuanced picture of me at a given time.

I also have more technical notes. Those are a bit of a "collection of facts". It's a bit like putting all the parts on the table, and slowly organising them into a coherent structure. This is how I approach bigger topics before I understand them fully. Then my notes act as a sort of medium-term memory. When I finish a project, I usually have a bunch of leftover notes and todos that I don't intend to ever finish. That's why I say that notes are not an obligation.