Frankly, I thought it was impossible -- that there was no way this could ever happen. But then 2008-2009 hit and proved me completely wrong.

It's not what you think !
You might be assuming I'm talking about AIG (NYSE: AIG) single-handedly destroying billions of shareholder wealth, Fannie Mae (NYSE: FNM) collapsing overnight, or even my typically steady Coca-Cola (NYSE: KO) shares taking a sharp dive. But I'm actually referring to something much more painful for me personally: college football.

You see, my grandfather played football for Oklahoma, and I've been a Sooners fan since I was old enough to walk. So it was nothing short of devastating to watch Oklahoma lose its fifth straight BCS bowl game -- and its third straight national championship game -- to Ol' Tim Tebow and team this January.

Of course, I'll always be a Sooners fan, even though they're now the Buffalo Bills of college football. After all, in sports, sticking by your team through the ups and the downs is a virtue. Just ask any Green Bay Packers fan.

Wall Street is a different ball game
For proof, just ask any longtime "fan" of:

Stock

10-Year Return

Home Depot (NYSE: HD)

(30%)

Yahoo! (Nasdaq: YHOO)

(57%)

Xerox (NYSE: XRX)

(81%)

Blockbuster (NYSE: BBI)

(90%)

Data provided by Yahoo! Finance.

Or ask my fellow Fool Rich Greifner. Or even ask Jim Cramer. In his book Real Money, Cramer reminds investors, "This is not a sporting event; this is money. We have no room for rooting or hoping."

Yet it happens all the time. Investing message boards are full of desperate investors who hope some cash-rich behemoth will come along and save their decades-old American superbrand. But as Circuit City investors found out, this is often a losing bet -- especially in this credit-strapped market.

Others ride stocks all the way into the ground because they're emotionally attached to the company's story, products, or management -- and meet with similarly dismal results. Take Crocs investors as an example.

Ditch that loser!
One of the "20 Rules for Investment Success" from Investor's Business Daily is to "cut every loss when it's 8% below your cost. Make no exceptions so you'll avoid any possible huge, damaging losses."

To a sports fan, that advice might seem cruel and unusual, but it's actually good investment advice.

Or is it? To find out, I dug through David and Tom Gardner's Motley Fool Stock Advisor picks. They often re-recommend a stock even after a big run-up -- or a sharp fall. I actually found three examples where breaking IBD's rule actually paid off big-time:

Stock Advisor Pick

Decline After
Recommendation

Gain After
Re-Recommendation

Netflix

23%

241% Continued...