You have to smile.
- It makes you attractive.
- It changes your mood.
- It is contagious.
- It relieves stress.
- It boosts your immune system.
- It lowers your blood pressure.
- It releases endorphins, natural pain killers and serotonin - natural antidepressant.
- It lifts the face and makes you look younger.
- It makes you seem successful.
- It helps you stay positive.
p/s: totally not mine. copied it somewhere :D