Almost two years into ambulatory work with the Brooke, my notes live in at least five places: a pocket notebook that has been rained on more than once, photos on my phone, a few pages in Evernote, the backs of treatment forms, and my memory. The last one is the least reliable.
Last month I saw a case I was sure I’d seen before. I even remembered writing something useful about it. I couldn’t find it, so I went back to the textbook and started from zero.
That’s when it clicked. I’ve been collecting notes for years. I haven’t been keeping them.
Collecting isn’t learning
Most of my notes are organised by where they came from: a lecture, a training course, a date. That makes them easy to write and almost useless to read. To find anything, I first have to remember when and where I learned it, which is exactly what I can’t remember.
Sönke Ahrens describes this trap in How to Take Smart Notes. We underline in one place, scribble in the margins somewhere else, keep ideas in a notebook and excerpts in a folder, and then rely on memory to connect it all. The notes pile up. The understanding doesn’t.
A note I can’t find is worse than no note, because I think I have it.
A better model
The best model I’ve found is decades old. The German sociologist Niklas Luhmann kept a Zettelkasten, a slip box: tens of thousands of index cards, each holding one idea in his own words, numbered and linked to related cards. He described it as a partner he could have a conversation with, one that surprised him with connections he’d forgotten making. It helped him write dozens of books and hundreds of articles.
Vannevar Bush imagined something similar in 1945: a desk he called the memex, which would store everything a person read and link it by association. His reason still holds. The mind doesn’t file things alphabetically or by date. It works by association, one idea pulling up the next.
The index cards aren’t the point. The principles are:
- One idea per note, small enough to link, reuse and improve.
- In my own words. If I can’t explain it simply, I don’t understand it yet.
- Linked, not just filed. A note is worth as much as its connections.
- Revisited. A note should get a little better every time I open it.
What this means for clinical notes
This is how I’m going to apply it:
- One note per concept. A disease, a drug, a procedure, a normal value. “Strangles”, not “Training, day 3”.
- Cases link to concepts. Each case gets a short note with the signs, what I did and what happened, and no owner’s details. It links to the disease note, and the disease note links back. Over time, every disease note becomes my own small textbook chapter, with cases from the field instead of pictures from someone else’s hospital.
- Written for tired me. The person reading these notes is me, at the end of a long day, on a call with a weak signal and a horse that won’t stand still. So: short, practical, what to check first, what to do next, and doses I’ve double-checked.
- Kept alive. When I see the disease again, I update the note. When I find out I was wrong, I fix it and write down why.
Personal notes too
The same idea works outside the clinic. When I read a book, I’ll try to write what I think, not a summary of what the author said, and give each idea worth keeping its own note. The same goes for lessons from work, ideas for projects and questions I can’t answer yet.
The test is simple: will this note still be useful in five years?
Tools
For now I’m using Evernote, because it’s on my phone, it searches well and it can link notes to each other. But I’m trying not to care much about the app. Plain text will outlive most apps, and the hard part isn’t the software. It’s the habit of writing the note properly, the first time, while the case is still fresh.
If this works, in ten years my notes will be the most useful book I own, because I wrote it one small note at a time.
Update, 2026: evergreen notes
I kept going. The notes went through more apps than I’d like to admit, settled in Obsidian, and the clinical ones are now public on this site as Clinical vet notes.
About eighteen months after I wrote this, Andy Matuschak began publishing his working notes and gave this kind of note a better name than any I’d come up with: evergreen notes, which he describes as “written and organized to evolve, contribute, and accumulate over time, across projects”. His principles read like a cleaner version of what I was fumbling towards in 2018: evergreen notes should be atomic, concept-oriented and densely linked; associative links beat hierarchical folders; and you should write notes for yourself by default.
That last one explains why some of my notes will look rough to you. They were written for a tired vet on a call, not for a reader. I still think that’s the right trade.
References
- Ahrens, S. (2017). How to Take Smart Notes. soenkeahrens.de
- Luhmann, N. (1981/1992). Communicating with slip boxes: an empirical account. Translated by Manfred Kuehn. luhmann.surge.sh
- Bush, V. (1945). As we may think. The Atlantic, July 1945. theatlantic.com
- Matuschak, A. Evergreen notes. notes.andymatuschak.org