For many people, “as soon as you start pursuing perfect sleep, it negatively impacts your sleep quality,” sleep researcher and former sleep coach Drew Copeland tells Popular Science. “Half of your sleep in the night is supposed to be light sleep,” Baron says. “[Sleep stages] can only be scored visually by a human,” Grandner says. What’s more, sleep stages are less important than people think. If you think that you may be overly focused on your sleep data, take a break from tracking.