Self, please note that if it’s after 1:00 p.m., and you’re starting to feel run down, and you think “maybe I should just skip lunch so that I can save time and get this work done,” what will inevitably result is an afternoon where you are working at 35-50% efficiency. If you take 30 minutes and eat lunch, you’ll bounce back to peak efficiency, and more than make up for the “lost” 30 minutes. Really.