Happy Ten-Ten Day!

It's October 10th, or Ten-Ten day, and by ancient family tradition,
that means Chinese food for dinner.

There is a standard, two step response that everyone has on learning this:

1) Yum!
2) Why?

The normal responses:

1) Yum!
2) I have no idea.

There have been many theories put forward to explain Ten-Ten day:
Archie comics, never before heard of "Chinese holidays," my Dad's
crazy roommate in college, etc. In truth, like all good traditions,
the origins are lost in the mists of time.