What exactly is the Dow Jones Industrial Average, the mythic number that punctuates each day's stock market report? I've always wondered. Now, with the Dow crossing 12,000, I decided to roll up my sleeves and delve into what that 12,000 really means. Why should I care — and why should you?

When the Dow is at 12,000, that's not 12,000 dollars, obviously; nor does the Dow reflect the performance of 12,000 companies (the index only reflects 30 companies) — nor does the 12,000 have anything to do with the number of shares traded each day on the stock exchange (that's in the millions).

To wax philosophic, the Dow is at once larger than the sum of its parts — and less. To understand the Dow is to gain entry into a vital part of the investing world. In short, it's all about indexes. (Or indices, if you prefer.)

Infidelity is always devastating. But if your spouse or partner has been cheating on you by hiding pricey vices or illicit spending sprees, the consequences can be far worse than an affair, for the simple reason that money — often large sums of money — are involved.

As one reader wrote to us, after a similar article ran on on DailyWorth:

My ex took out a credit card in my name and ran up $40,000 debt without my knowledge. Now I'm paying it off. I asked the credit card company to investigate the matter as fraud, but they didn't. It doesn't seem like I have many rights. As I found out, there were many secrets behind the numbers. Right now, I'm waiting for the divorce to come through.