There are 6 reasons behind this.
1. With this, you can remember your past happy moments and feel happy all the time without stress.
2. You can get energy for fighting with your current situations.
3. You can feel more positivity in your body.
4. You will feel more healthy.
5. You can increase your trust level.
6. Smile is free capital.
If you have any doubt regarding this, please talk me at my mobile no. 9356234925