Some people live for their jobs. I just don't know any of them.

For the rest of us, work is a means to support ourselves and our families. If you're in that group with me, you've probably asked yourself whether you'll ever be able to retire -- and if so, when.

Unfortunately, that apparently simple question has a fiendishly complicated answer. It depends on many projections about the future. Some of the bigger ones include:

  • How long you'll live
  • How well your health and independence will hold out
  • How bad inflation will be
  • How well your investments will perform
  • How much you'll be able to save every year between now and retirement
  • What kind of retiree benefits you'll receive

If you could accurately project those results, it'd be fairly straightforward to plug your current financial data into a spreadsheet and come up with The Answer.

Get real
Answers are never quite so simple. You could, for instance, give France's Jeanne Calment a run for her money as the world's longest-living person. Likewise, depending on your investment strategy and the whims of the market, your overall portfolio performance could be all over the map.

Just think back to the 1970s and the Nifty Fifty stocks. Those were supposedly "one-decision" stocks that you could buy, hold, and forget about forever. Yet looking through that list reveals a number of less-than-ideal results over the ensuing decades. Even ignoring those like Joe Schlitz Brewing, Polaroid, and S.S. Kresge, which these days no longer exist as independent companies, their results haven't all been stellar. For instance:

Company

Price on
1/2/1970

Price on
11/16/2007

Total Gain

Xerox (NYSE:XRX)

$17.42

$15.82

(9.2%)

J.C. Penney (NYSE:JCP)

$12.31

$43.19

250.8%

IBM (NYSE:IBM)

$18.24

$104.79

474.6%

International Flavors & Fragrances (NYSE:IFF)

$6.86

$48.84

611.7%

Lubrizol (NYSE:LZ)

$7.81

$62.95

705.8%

S&P 500

93.00

1,458.74

1,468.5%

Coca-Cola (NYSE:KO)

$1.71

$62.62

3,554.4%

PepsiCo (NYSE:PEP)

$0.86

$74.15

8,569.7%

All data split-adjusted.

Sure -- caffeinated beverage giants Coke and Pepsi have gone on to do quite well over the ensuing decades, but oh so many others have failed to keep up with the overall market. Sure, there were some stunning successes from the Nifty Fifty, but there were certainly enough failures to make it clear that they were anything but "one decision" stocks. The key lesson is that an investment strategy based on "set it and forget it" runs a serious risk of failing.

A lifelong journey
When you look at the big picture of your retirement, it should be clear that your future has many moving parts. As a result, there's no simple answer to the question of whether and when you can retire.

Don't let that stop you from trying to get there, though.

The good news? You don't have to take that journey alone. My colleague Robert Brokamp is a master at helping you build the plan you need, and his Motley Fool Rule Your Retirement service is a great way to take your retirement planning from idle pondering to plotting for success. If you're ready to build the plan that can take you from here to retirement, then click here to start your free 30-day, no-obligation trial.

This article was originally published on Oct. 3, 2007. It has been updated.

At the time of publication, Fool contributor Chuck Saletta did not own shares of any company mentioned in this article. The Fool's disclosure policy hopes to live to at least 123.