I have this problem with a lot of DS games that expect you to write an essay or draw a masterpiece in order to remember information you need for a puzzle, or (in Professor Layton's case) to complete a simple algebra problem. My rail maps eventually became very, very cluttered with \"information\".
At one point, I started using symbols instead of words and word-like things, but if you come back to it a week later and forget what it means, what was the point of writing it down in the first place?
You can watch this comic being drawn
HERE.