A trancelike state settles over your efforts; the climb becomes a clear-eyed dream. Hours slide by like minutes. The accumulated clutter of day-to-day existence – the lapses of consciousness, the unpaid bills, the bungled opportunities, the dust under the couch, the inescapable prison of your genes – all of it is temporarily forgotten, crowded from your thoughts by an overpowering clarity of purpose and by the seriousness of the task at hand.