Storytellersunplugged did a post on Beginnings in which the posters included a list of "strange rules regarding beginnings." The third one was "Never Start a Story with Weather."
I sat there thinking, Ah...what?
Then I recalled the most famous weather-related first line ever written. "It was a dark and stormy night." Hmmm. That's thought-provoking.
At about the same time that Storytellersunplugged was posting on Beginnings, The Spectacle did one on Famous First Lines. I was impressed by the number of first lines by famous writers that began with the verb "to be." "It was a bright cold day in April, and the clocks were striking thirteen" from George Orwell's 1984. "There was a boy called Eustace Clarence Scrubb, and he almost deserved it." – C. S. Lewis, The Voyage of the Dawn Treader.
My graduate school career was limited to one class (which I did ace, just so you know), and the only thing I learned during it was never to start a sentence--particularly an important first sentence--with the verb "to be."
Perhaps if I become a famous writer, I'll be able to get away with it.