I need help finding a funny email I was forwarded a long time ago. Do you remember it?

I am not sure if the details are exact because I got the email a long time ago, but I think it was about a man who would not engage in road rage because of a mathmatical equation he figured out. He figured out the statistics of how many drivers are women, how many carry a gun, how many have mental illness, and how many are on PMS. Out of all the drivers he pes on his daily commute, the man figures that statistically several of them are mentally ill women with PMS who carry a gun. Therefore, he does not get mad at other drivers. Does any body know where I can find this so I can copy it and send it to a friend?