The difference in life between success and failure, more than anything else, is having a plan and sticking to it.

Whether you’re talking about launching a business, getting through Navy SEAL training, becoming a concert violinist, or even getting a date on Friday night; success comes from seeing a plan through to completion.

This is particularly true when it comes to investing.

Warren Buffett, the legendary Oracle of Omaha and by most accounts the most successful investor in history, is probably a little smarter than you or me. I say “probably” because Mr. Buffett has never published his IQ score, and measurements of intelligence can be subjective.

But, in Buffett’s own words, in order to be a great investor, “You don’t need to be a rocket scientist. Investing is not a game where the guy with the 160 IQ beats the guy with a 130 IQ.”

To put that in perspective, the average IQ falls in a range of about 85 to 115. An IQ over 140 is considered genius level, and theoretical physicists Albert Einstein and Stephen Hawking were believed to have respective IQs of about 160 each.

So, according to Buffett, you need to be a little above average to be a good investor. But you certainly don’t need to be an Einstein or Hawking.

Buffett attributes his own success to “being greedy when others are fearful and being fearful when others are greedy.”

In other words, Buffett is Buffett not because of his intelligence but rather due to his emotional control, which allows him to stick to an investing plan even when most other investors are pulling the ripcord.

Now, I don’t claim to have Warren Buffett’s talents. But some of my greatest investment successes have come from being equally stubborn about seeing a plan through to completion.

I don’t have a large enough nest egg to retire today. But it’s big enough that I don’t really need to keep adding to it with fresh savings. Even with very modest growth assumptions, the savings I’ve accumulated already should be more than sufficient to take care of me and my wife in retirement when that day comes in another 20 years. Savings I continue to add just put the icing on the cake.

It wasn’t fantastic investment returns that got me to this point. It was having a savings plan and having the discipline to see it through to completion. I max out my 401k contribution every year, even when doing so is painful. Even when the market looks scary. Even when I’d prefer to blow the cash on something else or when I have to tell my children that I can’t afford something they want right now.

I’ve enjoyed competitive returns on those funds over the years, but the high savings rate has had a much bigger impact on my ability to grow my capital base than my returns.

As another example, I bought 288 shares of Realty Income (O) in 2009 that I swore at the time I would never sell. I committed to reinvesting my dividends into new shares and letting it compound… for the rest of my life. My children may sell the shares when I’m dead and in the ground, but I never will. When I’m old and gray, I’ll simply turn off the dividend reinvestment and take them in cash instead.

Well, after a little over nine full years of dividend compounding, those 288 shares bought for an initial purchase price of $6,620 are now 454 shares worth $32,383.

Using conservative assumptions on dividend growth, I would expect my investment to double every eight to ten years. So, in another 20 years, when I’m getting close to retirement, I’ll have something in the ballpark of $140,000 in Realty Income… still trucking along and throwing off dividends. And all of that on an initial investment of just $6,620.

Now, I’m not recommending you run out and buy Realty Income. I wouldn’t make a major new purchase at today’s prices. My point is simply that having a good plan – in this case buying and holding a high-yield dividend stock bought at crisis prices – works when you actually stick to it.