Sad song lyrics

`You may think I look sad
But I am just sleeping
It's my facial expression
I'm probably dreaming
Would you like to be sad?
Would you like me to teach you?
Well, you can learn to be sad
But you must practice like I do
Na na na, na na na na ...
You must follow directions
And learn it right from the start
There isn't a short cut
It must come from your heart
Well there are those who are happy
And there are those who are wise
But it's the truly sad people
Who get the most out of life
Na na na, na na na na ...
You may think I look sad
But I am just sleeping
It's my facial expression
I'm probably dreaming