podcast about happiness

I heard a podcast of Yael and it talks about happiness.
The podcast starts pessimistic and she says how people might feel, lonely, without friends, sad etc.
But then Yael changes the music and says what we can do. Start smiling. In addition Yael explains who one can achieve it, by going to a good film, listening to the music, etc.
For me the main sentence is: Smile and the world will smile back to you!
I liked because this podcast is really true. Many times I feel that if I smile people smile back, but not always it is easy to smile, especially in those days but probably even though we should try to smile.:)