I Whistle a Happy Tune

Whenever I feel afraid, I hold my head erect
And whistle a happy tune, so no one will suspect I'm afraid
While shivering in my shoes, I strike a careless pose
And whistle a happy tune, and no one ever knows I'm afraid

The result of this deception is very strange to tell
For when I fool the people I fear, I fool myself as well!
I whistle a happy tune and every single time
The happiness in the tune convinces me that I'm not afraid
Make believe you're brave, and the trick will take you far
You may be as brave as you make believe you are