Contagious Smile?

Why are people telling me that

Seeing my smiles made them happy and brightens up their day?? 🤷🏻‍♀️
Why are people asking me to be happy always?? 🤷🏻‍♀️

Does my smile really have the ability to cheer one’s day up?
Does my smile really have the ability to bring joy to the people around me?

Do I really have a contagious smile??