My friend and fellow sketchnoter Boon Chew has written an excellent article — Sketchnotes as part of a maturing creative practice — after hearing from some people that simply looking at others' sketchnotes wasn't always satisfying.
Boon's point in this piece is that, as I say in my book, sketchnotes are personal and for you first — others second. The fact that sketchnotes are often beneficial to others is a great benefit, but not the immediate purpose for doing them.
He writes for user experience practitioners, but I think the message resonates for anyone doing sketchnoting or other visual thinking practices to keep those creative muscles active.
Go have a read and leave your comments on Boon's site.