Remember Rip Van Winkle? He took a nap and didn't wake up for 20 years. Rip probably wouldn't be the best investor in today's world -- or would he? Are there stocks that a person could buy today and hold for 20 years without worrying about them? While few stocks merit this type of confidence, I think Coca-Cola (NYSE: KO) does. Here are two reasons why.

Enduring demand
If you're taking the Rip Van Winkle approach to buying a stock, you want a high degree of confidence that the company's products will still be selling well at the end of 20 years. Will Coke lose its sales fizz over two decades?

Consider that the company has been around for 125 years yet demand for its products is still increasing. "Coca-Cola" has been documented to be the second most widely recognized term in the world -- after "OK." On average, every person on earth consumed 92 servings of Coke beverages in 2011, according to the company. You could safely say that Coke isn't a passing fad.

In comparison, Monster Beverage (Nasdaq: MNST) has been around 22 years. Their energy drinks and other beverages are quite popular, with sales of nearly $2 billion in 2011. But could you envision a scenario where the company isn't as successful as the past? The thought of buying Monster Beverage without frequently reevaluating the stock seems scary.

Endearing dividends
When you're looking at holding a stock for 20 years, dividends make a big difference. Coke currently has a 2.6% dividend yield. The company also has a history of 50 consecutive annual dividend increases with an average increase of 9.8% over the past 10 years.

Here's what these numbers mean. Let's say you bought Coke stock today and reinvested all dividends into more shares. If the company continued increasing its dividend at the same rate as it has in the past decade, your account value would roughly quadruple in size by 20 years from now -- assuming the stock price didn't change by a penny.

Granted, this calculation didn't include taxes on dividend payments nor did it include the impact of inflation. Then again, we assumed a nonsensical premise that the stock price wouldn't increase: Coke shares increased more than 360% over the past 20 years, without counting dividends.

Rival Pepsico (NYSE: PEP) looks good on the dividend front, too. The company has raised its dividends for 40 consecutive years with an average increase of 14.1% over the past 10 years. There must be something in the carbonated water.

Sleeping with a smile
Anything can happen over a long period of time. Even a stellar company like Coca-Cola could potentially stumble. Checking on your investments regularly is a good idea.

There is wisdom, though, in buying stocks that you wouldn't mind holding for 20 years or more. Coca-Cola is an exceptional company that you could own for a long time. If you want to take an extended nap, buying Coke will help you sleep -- and wake up with a smile.

Stocks like Coke that pay great dividends have made investors smile for years. To learn about more great dividend ideas, check out The Motley Fool's new free report, "The 3 Dow Stocks Dividend Investors Need." Get your copy by clicking here.