Do you know that yawn is not bad and you should do it even when not feel sleepy?

There are 12 main reasons why to yawn :

1. Switch wakefulness and alertness.
2. Optimize brain activity and metabolism.
3. Improves mental function.
4. Increase the memory recall.
5. Enhanced consciousness and introspection.
6. Reduced stress.
7. Every part of the body relaxes.
8. Improves voluntary muscle pain.
9. Improve sports skills.
10. Coordinated precisely the feeling you have for the year.
11. Increasing understanding and social awareness.
12. Enhances the pleasure and sensuality.