Why We Sleep
SLEEP is one of life's most universal needs — every animal sleeps in some form. Humans spend ~1/3 of life asleep. For decades, sleep seemed mysterious — why would evolution make us VULNERABLE for hours each night? Modern research has revealed: sleep does VITAL work. Memories consolidate. The body repairs. Emotions process. Toxins clear from the brain. Without enough sleep, every body system suffers.
Functions of sleep. (1) MEMORY consolidation: experiences from the day are sorted and stored. (2) BODY REPAIR: tissues regenerate; immune cells produced. (3) BRAIN CLEANING: the glymphatic system flushes metabolic waste (including beta-amyloid, linked to Alzheimer's). (4) HORMONE regulation: growth hormone, cortisol, leptin all rhythm with sleep. (5) EMOTIONAL processing: REM sleep helps regulate mood. (6) GROWTH (especially in kids). Sleep is when much of "being healthy" actually happens.
Pulling an all-nighter to study before a test typically RESULTS IN:
Sleep needs by age. NEWBORNS: 14-17 hours. TODDLERS: 11-14. KIDS (6-13): 9-11. TEENS: 8-10. ADULTS: 7-9. ELDERLY: similar but more fragmented. Most teens are chronically sleep-deprived (school start times, screens, social pressures). Sleep deprivation is linked to: lower grades, more accidents, depression risk, weight gain, weakened immunity. It is not a luxury — it's a need.
Sleep Audit
For 3 nights, log what time you slept and woke up. How many hours? How'd you feel? Most people don't actually track. The data often surprises. Try going to bed 30 min earlier for a week — notice changes.
Sleep is one of the most powerful things you can do for your body and mind. Free, non-medical, unbeatable. Many adults treat sleep as expendable; they pay the price in health and performance.
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