I scribble in notebooks a lot too, but it's very rarely anything resembling pseudocode or any representation of the actual algorithm I'm working on. It's usually just a todo list, with occasional things heavily underlined so I don't forget them. I often do something similar at the end of the day if I need to remind myself where I left off. For me, it's not at all comparable to whiteboard coding.
Yesterday. Although, usually I pull out a notebook instead, and work things out with colleagues (or on my own) on paper at my desk. That happens several times a day.