Machine or computer? As a graduate student it may sometimes feel like you're supposed to be a machine. Running constantly and churning out consistently awesome work from day one without any need for input from others. Take a moment and ask yourself, "Am I comfortable with reducing my activity for a while?" Or how about, "Am I comfortable with NOT doing a single thing for a while?" Whoa. Being completely inactive just makes me nervous and paranoid.
Becoming ok with not doing anything, surprisingly, takes work.