Sucking in radon and making saws takes a lot of concentration. It’s nice to have a shop notebook handy where I can write things down so I don’t have to think about them anymore. I do this all of the time. It helps me focus on my work without either forgetting whatever it was that was worth writing down.
The shop notebook isn’t always the place where the most important things get written down—I don’t need to write that stuff down. That stuff gets written straight into the saws. But even so, and perhaps for that very reason, the notebook has a unique proximity to my work—not the most important stuff, but indispensable stuff. New ideas, sketches, problems and how I solved them, nitty gritty details about more peripheral things I don’t have occasion to make every day.
I can’t imagine that anyone who spends a significant amount of time in their shop wouldn’t benefit from keeping a notebook around. It’s amazing how clearly you can focus on your work when you have someplace to unload your thoughts.