In 2002, the Investment Company Institute, the industry group for mutual fund companies, found that just about half (52.7 million or 49.5%) of all U.S. households owned stock in some way.  But just 21 million households (fewer than 20%) owned individual stocks outside their 401(k) plans and other mutual funds.

I know that much has changed since 2002, but I’m betting that those figures are still in the ballpark.

And that’s because owning mutual funds is easy.

If you own a chunk of a fund that owns a basket of stocks, you don’t have to watch the daily movements of stocks and make decisions about buying and selling.  (The mutual fund companies certainly work hard enough to discourage you from taking much initiative with your investments.)  Plus, if you have a tax-deferred mutual fund, you don’t have to consider the tax consequences of capital gains.

Personally, I have the bulk of my retirement savings–what’s left of it anyway–in exactly the same kind of mutual funds as most people.  They are mostly a legacy from my days with earlier employers, and I mostly just let them be.

But I also own individual stocks.  And I think there are some really good reasons for taking on that role.  Here they are.

1) Owning stocks is real.

Facebook, Twitter, YouTube, Second Life, chat rooms, massively multiplayer online role-playing games and every game console joint ever made may be fun, even addictive.  But life online doesn’t make or lose a thing.

But if you own a stock, you’re joined at the wallet to the fortunes of the company that issued it.  It’s real money, and you can make actual money with it.  You can also lose money, but that’s part of being real.  You can’t hit restart or (command/option/escape) and make it go away.  Real risk, real opportunity.  There’s nothing like making a decision and having it lead to real consequences.

2) Owning stocks gives you a chance to test yourself.

It’s one thing to watch the markets in a general way.  And you may find yourself making some interesting adjustments to your mutual fund allocations during the open enrollment at the end of your company’s plan year.

But owning stocks allows you to test yourself against Warren Buffett, Gordon Gekko and Jesse Livermore, the Speculator King.

How good are you at picking the nuggets out of the gravel?  Do you have the nerves to wait out a market correction and the gumption to follow a sell discipline?  If you’re willing to pay for the class, the market will be more than happy to give you exactly the grade you deserve.  It can be a humbling experience at times, but also personally rewarding.

3) Owning stocks is fun.

It amazes me all the time that people go to Las Vegas knowing that they’re probably going to lose money … and yet they enjoy themselves.  But then that’s what huge fountains, famous headline acts and billions of dollars of advertising and fantasy architecture will do for you.

The stock market, on the other hand, just has the boring old ticker.  Stocks and indexes go up and they go down.  You have to supply the fireworks.

But if you’ve ever talked to an investor who owns a stock that has just doubled in six weeks, you’ve probably seen something akin to real joy.  (Yeah, I know that it’s nothing compared to parenthood, finding true love and sinking a hole in one, but you have to work with me here.)

I also know that it may not be fun if you’re desperately playing catch-up, trying to get your retirement funds back up to where they should be so you can quit a job you don’t like and head for the ivy-covered cottage in which you hope to live out your years.  I’m not saying it’s fun for everyone.  But for people who prefer investing to woodworking or collecting Pez dispensers, it can be a hugely enjoyable thing to do.