In fact, smiling is considered today as one of the most important things when conducting a business, selling a product or when conducting a job interview. In addition there are coachs and gurus who talk about laughter yoga (I have practiced several techniques and I have felt very good) that help improve mood.
I can confirm from my experience that smiling has been fun, and I have felt more willing to achieve my goals.
In general, having a good attitude always leads to a better destination !, so to smile and change the world !.
I love the way you ended your comment. Smile indeed changes the world. Keep smiling buddy