I have two stacks on my desk: a sketchbook with bent corners and tea stains, and a folder of finished pieces I might one day call a portfolio.
The sketchbook is where the work actually happens. It's full of half-thoughts, things that didn't work, things I'll redo three more times until they do. The portfolio is the polite version — the one I'd show a stranger.
Both matter, but for different reasons. The portfolio is for other people. The sketchbook is for me. When I forget which one I'm drawing in, the work gets stiff. The trick, I'm learning, is to keep them honest about what they are.