Three days of a market rally produced S&P 1,400, Nasdaq 3,000 and Dow 13,000-and-change. Yes, it has been a while since all three major indices were above those levels at the same time — but as much as round numbers and surmounting 100-point or 1,000-point marks are neat and tidy milestones, they don’t mean squat when it comes to the future direction of stocks.

So enjoy them while they last.

The S&P 500, the most commonly used benchmark for the broader U.S. stock market, closed above 1,400 Tuesday for the first time since May 1. The Dow Jones Industrial Average, the most commonly cited shorthand reference for the market, is likewise back at early May levels. So is the technology-focused Nasdaq Composite index.

One big push will put the market back not only to its 2012 high, but its bull-market peak of 1,419.

Too bad stocks don’t care about big, round numbers.

Yes, technical levels matter, if only because traders — be they humans or algorithms — actually respond to such things. When the market breaks through resistance or support, technical trading can make its upward or downward trend become a self-fulfilling prophecy. The market goes down because the technicals say it should. Sell signals beget more sell signals, and so selling can take on a life of its own.

The big so-called psychological levels — like Dow 12,000 or Dow 13,000 — used to mean something, maybe. They were thought to have significance, especially for the great mass of retail money.

The allure of rising prices is hard for anyone to resist, whether it’s in tech stocks, home prices or tulip bulbs. As stocks rise, more people want to take part. They are, after all, the only thing people want more of when they’re expensive, not cheap.

But after two major market crashes in little more than a decade, it looks like it will take years of rising markets — perhaps well above record highs — to get retail investors to embrace stocks again.

Money has been rushing out of equity mutual funds for four years now. It’s flooding into bond funds (which is partly why interest rates are so low). Mom-and-pop investors are fed up with seeing giant chunks of their wealth wiped out in the market.

And even though the major indices have put up remarkably good gains in 2012, they’ve done so with gut-wrenching volatility and still are below all-time peaks.

The S&P 500 is up a healthy 12% this year on a price basis, but that’s still almost 11% below its pre-crisis high notched in October 2007. (Add in inflation, and it has fared even worse.)

The Dow is up almost 8% for 2012, but that’s still 7% below the all-time closing high of 14,164 hit almost five years ago.

And the Nasdaq … well, forget it. The index’s 18% year-to-date gain is something to behold. But more than 12 years after the dot-com crash, it’s still off a whopping 40%.

Stocks never move in a straight line. S&P 1,400 doesn’t guarantee stocks will hold that level. And now that retail investors aren’t getting suckered by such headlines, it’s even easier for the gains to disappear in a flash.