Unusual ideas are difficult to communicate.

The first step is to understand them thoroughly. As far as I know, the best way  to work through a set of ideas is to visualize them.

A few years ago, I scribbled some sketchnotes from Göran Backlund's book "Refuting the external world". (Read at your own peril!)

The drawings were done pre-iPad - days. I drew on paper, scanned, and added color in Photoshop.

They are only rough sketches meant to help me understand Göran's argument.

It is interesting to revisit those old sketchnotes.

I hadn't thought about the book for years – and when I see the drawings, the ideas come to life immediately.

Honestly, I don't know how people understand difficult material without drawing it.