Confidence about sleep is common — after all, most of us have been sleeping our entire lives. But confidence doesn’t always equal understanding, and a physician recently demonstrated this point with five sleep facts that genuinely surprise most people. The biggest surprise: women need more sleep than men, and it’s not because of preference or habit — it’s biology.
The reason centers on the demands of multitasking. Women tend to engage in more simultaneous cognitive processing throughout the day — managing multiple lines of thought, responsibilities, and tasks at once. This heavier cognitive workload means the brain has more to do during sleep: more memories to consolidate, more information to organize, more neural resources to restore. The estimated difference is about 20 additional minutes of sleep per night for women.
Sleep onset — the transition from wakefulness to sleep — is also more informative than most people realize. Ideally, this process takes 10 to 20 minutes. Falling asleep significantly faster may feel like an efficiency win, but it often indicates accumulated sleep debt. Taking 30 or more minutes consistently may point to insomnia or other conditions that make it difficult for the nervous system to shift gears toward rest.
Dream loss is one of the most consistent phenomena in sleep science. About 95 percent of our dream content disappears within a few minutes of waking, because dreams don’t get transferred into long-term memory the way waking experiences do. For those who want to understand their dreams, the only reliable solution is to write them down immediately upon waking — before anything else takes priority.
The physician’s final two insights are both practical and important. Seventeen hours of uninterrupted wakefulness produces cognitive impairment equivalent to a blood alcohol concentration of 0.05 percent, which is enough to compromise performance in many critical situations. And with melatonin, less is more: 0.5 mg mirrors the body’s natural production and is typically more effective than the larger doses that fill pharmacy shelves.
