. . . . . Tell Me Why
Tell me why the stars do shine,
Tell me why the ivy twines,
Tell me why the sky's so blue,
And I will tell you why I love you.
Nuclear fusion makes stars to shine,
Tropism makes the ivy twine.
Rayleigh scattering makes skies so blue,
Glandular hormones are why I love you.
. . . attributed to Isaac Asimov