Smile though your heart is aching
Smile even though it's breaking
When there are clouds in the sky, you'll get by
If you smile through your fear and sorrow
Smile and maybe tomorrow
You'll see the sun come shining through for you

Light up your face with gladness
Hide every trace of sadness
Although a tear may be ever so near
That's the time you must keep on trying
Smile, what's the use of crying?
You'll find that life is still worthwhile
If you just...smile

John Turner, Geoffrey Parsons and Charlie Chaplin