When I was in high school, my geography teacher forbid us from using pencils when we had pop quizzes. He said that professionals used pens and we ought to start getting used to it. He didn't know but I was already well aware that my future professional life was going to have a lot of pencils in it.
I've never drafted a full set of working drawings by hand. My first year studio classes at Kansas State University taught the Logo programming language instead of stippling and shading with pencils and technical pens. Soon after I learned AutoCAD and Form Z and fell under the digital spell. In my fourth year professor Bruce Johnson asked our studio to work with our hands directly - building models in foam and chip board and drawing on vellum. His goal was to make us commit to decisions and see through the consequences and to understand the physicality of making spaces. That challenge opened me to a new way of seeing architecture, bringing it closer. Of course as a student I was still far from getting anything I'd design built, but the veil of abstraction created in computerized space had been lifted.
I am not a Luddite, and do not advocate a full fledged return to analog methods. I support a hybrid approach, a tool-agnosticism where all options are available and useful depending on the situation at hand. Drawing by hand for me allows a slow, looping, layered process of thinking, acting and evaluating. Soft lines start defining a generalized notion. Repeated strokes build up as confidence and clarity increase. A fresh sheet of tracing paper is overlaid and harder lines commit the sketch with greater resolve. In discussions with colleagues we frequently talk and draw, each working through the detail we're trying to solve. Sketches record the thought process help us confirm we are talking about the same thing no matter how loose and geometrically imprecise they may be. The computer's real strength lies in helping us as designers see possibilities that would be barbarically laborious to do by hand. Cold calculation however must be guided by a warm heart.