Some very cold, very obscure facts:

1. The female reproductive limit is 72 years old, while for males it is 93 years old.
2. Sleeping for 5 hours is equivalent to 1.5 times that, and waking up feels more effective than sleeping 8 hours, staying alert all day.
3. The size of the human eyeball remains basically unchanged after age 6-8.
4. People are 1-2 centimeters taller in the morning than at night.
5. A person's lifetime saliva can fill two swimming pools.
6. Human hair can withstand a weight of 12 tons.
7. The energy generated by a person's heart each day can drive a truck for 30 kilometers.
8. Sweat hairs on human fingers all grow toward the little finger.
9. People tend to become angry when hungry, known as "hunger rage."
10. Human skin cells renew every 28 days.
11. The number of bacteria in the human body exceeds the number of cells.
12. Human feet sweat more easily than hands.
13. People tend to go to the bathroom more often in winter.
14. The thumbnail grows the slowest, while the middle finger's nail grows the fastest.
15. Hearing improves when a person is nervous.