1. The areas where a man has slept are oily and yellowish.
This is because men have more active sebum secretion, especially on the head and face.

2. Women's hearts are smaller than men's, but they usually beat faster.

3. The size of a person's eyeballs basically stops changing after age 6.

4. Smiling can lower the body's stress hormone levels and boost immunity.

5. Adults have fewer bones than children because some bones fuse together during growth.

6. The brain consumes about 20% of the body's total energy.

7. Like fingerprints, tongue prints are unique to each person.

8. A person's height is highest in the morning and lowest at night, with a difference that can be several centimeters.

9. You can't open your eyes when you sneeze.

10. The average person eats about 50 tons of food in their lifetime.

11. The length of the blood vessels in the human body could circle the Earth two and a half times.

12. A person sheds about 40 pounds of skin in their lifetime.