The author describes a context while he's debugging. I think an analogy would be a chess game, where the player has built/planned your stack of several 'look ahead' moves. And then you get interrupted. That can be indeed be very disruptive for a human brain. A computer can save that 'stack' and resume, not so for a human brain to recover your context. Programming has its unique things. Not to deny the other unique situations (underwater panel, clinician's analysis etc) that have been mentioned in the various threads of this discussion.