Sun valley serenade - I know why (and so do you)

Why do robins sing in December,
Long before the springtime is due?
And even though it's snowing,
Violets are growing,
I know why and so do you.

Why do breezes sigh ev'ry evening,
Whispering your name as they do?
And why have I the feeling
Stars are on my ceiling?
I know why and so do you.

When you smile at me,
I hear gypsy violins;
When you dance with me,
I'm in heaven when the music begins.

I can see the sun when it's raining,
Hiding ev'ry cloud from my view;
And why do I see rainbows
When you're in my arms?
I know why and so do you.