When's the last time that the satisfaction of owning shares in a company carried over past the end of the trading day? The very concept of equity investing is awfully empowering, but when was the last time it made you swell with pride as well?

If your answer falls somewhere within spitting distance of "never," maybe it's not you. Maybe it's just your portfolio.

Your stocks may be respectable performers. You may know each company well, or least more than just the prerequisite ticker symbol. But is that enough? Are you getting the complete investing experience?

You're not, by the way. If you find your voice dropping when it's time to discuss your holdings at a party, let's face it: You're ashamed of your portfolio. That kind of attitude may not necessarily destroy your wealth -- last time I checked, vanilla still sells briskly as an ice cream flavor. However, if it destroys your zeal for investing, your stocks may be doing you far more harm than any potential damage you see in your monthly brokerage statements.

Bringing back the butterflies
The easiest way to fall in love with investing again is to buy the companies that will get you excited about owning a stake in their future. If someone shouts, "I love Audible (NASDAQ:ADBL)" from the rooftops, it's not necessarily the delirium kicking in. It can be an impassioned plea, coming from someone who relishes the consumption of audiobooks and other spoken-word content through this leading subscriber service.

How about a company that may literally save your life? Or at least the life of someone you love? When Motley Fool Rule Breakers recommended shares in iRobot, the newsletter service didn't just stumble into a cool company founded by some MIT geeks. Household cleaning robots like Roomba and Scooba free up time that would otherwise be spent cleaning house, but while consumer robotics make up the largest share of iRobot's revenue mix, they're not the company's only offerings. iRobot is also a military contractor, thanks to its bomb-detonating PackBot mobile robots. Hundreds are stationed in military hotspots in Iraq and Afghanistan, and they have no doubt saved lives.

This is the kind of stock that feels right to own. It's not a matter of making a political stand, or even an ethical one. If you're buying into a revolutionary company that's about to change the world for the better, you'll find yourself more excited about charting its eventual success.

Shares of iRobot haven't appreciated -- yet -- since being singled out, but the average Rule Breakers pick is 5 percentage points ahead of the market average. Yes, you can own a stock that will put a smile on your face the moment you issue the "buy" order -- and make that smile grow even wider as it fattens your portfolio with paper profits.

Celebrating the goose bumps
Some of the biggest winners over the past year have done just that, even though their life-altering actions may not seem obvious at first. Chipotle Mexican Grill (NYSE:CMG) isn't just a fast-growing chain of Mexican eats. Its freshly prepared food can be healthier than some of the artery-clogging grub found at more conventional fast-food chains. Baidu.com (NASDAQ:BIDU) isn't just the leading search engine in China; it's the top gateway of information for a country of 1.3 billion information-starved citizens.

Even a company like Sun Microsystems (NASDAQ:SUNW) is the kind of enabler that would make you a proud owner if the shares were in your portfolio. How rich would your surfing experience be if it weren't for Sun's free Java technology? Even though many of its online software initiatives haven't caught on, where would many companies be without Sun's UNIX-based servers or its Solaris operating system?

Sift through your portfolio and ask yourself what your stocks have done for you lately. If you want some cool ideas, iRobot isn't the only Rule Breakers pick to enrich its investors by enriching the lives of others. Among the ranks of the active newsletter recommendations, you'll find some pretty impressive corporate heroes. Some of them are obvious, like the active biotech picks with rich pipelines, bent on enhancing the quality and length of our lives. Some of them are not as obvious, but are still rocking along with Dr. Feelgood. How about a company making airports and other venues safer? That's American Science & Engineering (NASDAQ:ASEI) in a nutshell, since it makes X-ray equipment and other scanning devices for the security and defense industries. What about a promising upstart that is making inventory control more efficient by assisting in the implementation of RFID (radio frequency identification) technology. That's Click Commerce (NASDAQ:CKCM) at work.

You can call it karma when the cool stocks work out. I call it common sense. Let's compromise and call it karma sense. In the end, the most exciting growth stocks are achieving their upticks by improving situations, which in turn has created fatter wallets. Want proof you can profit by doing the right thing? Check out our Rule Breakers community free for 30 days.

So, yes, you can change the world -- or at the very least, change your portfolio.

This article was originally published on Jan. 5, 2006. It has been updated.

Longtime Fool contributor Rick Munarriz feels that way too many investors dismiss the empowering experience of believing in the companies behind their investments. Rick is also part of the Rule Breakers newsletter research team, seeking out tomorrow's ultimate growth stocks a day early. He owns shares in Baidu.com. The Fool has a disclosure policy .