It's tough to invest successfully. You're putting your money at risk when you invest. You can wind up with less than what you started with. In addition, unless you pay a mutual fund manager to do your homework for you, you can expect to spend several hours a week researching potential investments.

Worst of all, though, is the reality that every penny you have tied up in an investment is money you can't spend to enhance your lifestyle today.

All of that seems to work against the one true aim of investing: growing your nest egg now to have more money later. You absolutely need to invest today if you want a shot at comfortable golden years.

Why the urgency?
Truth be told, your most important retirement asset isn't your cash -- it's your time. The longer you have before you must spend your money, the less you need to save per month (and in total) to have what you'll need when you need it. It's just the way compounding works.

Assume you're looking to retire by age 70 with $1 million socked away, and you think you can roughly match the market's historical 10% annualized return. These numbers show just how important time is to meeting your financial goals:

Years
to Go

Monthly
Investment

Total
Invested

50

$57.72

$34,633.25

45

$95.40

$51,514.42

40

$158.13

$75,900.37

35

$263.39

$110,624.19

30

$442.38

$159,257.65

25

$753.67

$226,102.24

20

$1,316.88

$316,051.95

15

$2,412.72

$434,289.21

10

$4,881.74

$585,808.84

5

$12,913.71

$774,822.68

If you thought coming up with $58 a month to invest at age 20 was tough, just try waiting until age 60 and finding nearly 80 times as much spare cash in your budget. No matter how you slice it, the sooner you get started, the less painful it'll be.

Start simple, but start now
Of course, deciding to invest for your retirement and actually doing something about it are two different things. With all the different investing options available to you, you may run the risk of "paralysis by analysis" -- not doing anything at all for fear of making the wrong choice.

The easiest way to get started is with a low-cost index fund like Vanguard 500 Index (VFINX). As the name implies, it's a one-stop shop that gets you invested in 500 of the largest and most profitable companies around:

Company

Market Cap
(in Billions)

TTM Earnings
(in Billions)

Weight in
Fund

Goldman Sachs (NYSE:GS)

$87.65

$11.35

0.71%

Abbott Labs (NYSE:ABT)

$84.80

$1.93

0.66%

Oracle (NASDAQ:ORCL)

$105.19

$4.44

0.64%

United Technologies (NYSE:UTX)

$72.70

$4.03

0.57%

Boeing (NYSE:BA)

$68.42

$4.01

0.55%

Target (NYSE:TGT)

$45.58

$2.96

0.36%

Caterpillar (NYSE:CAT)

$43.35

$3.45

0.35%

To have a reasonable shot at a golden retirement, you must get started now. At Motley Fool Rule Your Retirement, we want you to be able to do just what our name says -- rule your retirement. Your time is your most valuable asset. To help make the best use of yours, start a free 30-day trial of Rule Your Retirement here and now. Your golden years will thank you for it.

This article was originally published on June 4, 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 has a disclosure policy.