The Secret of the Buddha's Smile

A conversation i had a year ago:

Zeph: What is your answer to the first ever koan of "Why did the Buddha smile while holding a flower?"
Liuguang: He was simply enjoying the present moment, smelling the flower with awareness without attachment. Mahaksayapa saw this and understood- so he smiled back. This might be the Dharma transmission of no transmission! Simple and beautiful- no complications.
Zeph: Wonderful! It's so funny then... that so many of us create convoluted theories of some mysterious secret behind the smile :-)