MANAGING MONEY is ridiculously simple—and unbelievably hard.
Figuring out what we should do with our dollars is typically straightforward: We should save regularly, diversify broadly, rebalance occasionally and so on. Instead, the tough part is getting ourselves to do what we intellectually know is right.
Take the notion of buying low and selling high. Every investor knows that’s the goal—and yet, when the S&P 500 slumped 34% earlier this year, many folks just couldn’t bring themselves to buy stocks.

I BEGAN MY CAREER in investments as a junior analyst at a public endowment fund. It was 1980 and I’d just finished my last investment class at college, where I learned about Modern Portfolio Theory. Why, decades later, is it still called “Modern”?
The Dow Jones Industrial Average was below 1000, versus today’s 27000. Men wore suits in 100-degree Texas heat. We had individual offices. We researched companies by reading brokerage reports, talking to brokers and requesting annual reports from companies.

LIKE OTHERS, I TOOK my first part-time job as a teenager and, once working fulltime, stayed at it steadily for decades. Being an adult meant being a worker, affiliated with some firm or another, one industry or another.
My plans for ever exiting the labor force were vague: “Save for the future, so someday you will retire with honor and dignity to spend your waning days as you desire.” I saved steadily,

THIS IS THE STORY of a bitter life lesson that taught me two things: the desirability of managing my own investments and the perils of putting almost all my eggs in one basket.
In the late 1980s—and early in our marriage—my wife and I were busy raising four kids, while also managing two demanding careers. Our dream was to build a beautiful house on a large wooded lot that we owned in the hills west of Austin,

BY EARLY 2009, I HAD been investing for 22 years. My wife had invested for a bit longer, and our savings were starting to seem like a significant chunk of money. I was reasonably happy with our investments. Still, I knew that—for those 22 years—we had been paying too much in investment expenses, thanks to the high-fee funds in our employer-sponsored retirement accounts.
Another source of frustration was that our money was spread over seven financial accounts and 14 mutual funds.

INVESTING IS ALL about picking the “best” investments—or so I thought. It took a lot of years to realize that this was the wrong focus. Instead, selecting a portfolio of good, reliable investments and sticking with them is what really worked for me and for my clients.
Sound simple? It can be—but the maintenance is surprisingly hard. We’re talking here about periodic rebalancing. That involves setting target percentages for a portfolio’s various investments and then occasionally buying and selling,

IN THE BOOK OF JOAN, a tribute to the comedian Joan Rivers, her daughter Melissa shares some of her late mother’s quirks. Among them: Her mother always drove 40 miles per hour. Regardless of where she was—on the highway, in a school zone, in the driveway—she always drove 40 miles per hour. Melissa’s conclusion: For passengers, this could be hair-raising, but at least her mother was consistent.
When it comes to investing,

EVERY SO OFTEN, I’m asked about my biggest investment mistakes—and I really don’t have much to say. Yes, like many others, I dabbled in individual stocks and actively managed mutual funds early in my investing career. Yes, like everybody who’s truly diversified, there are always parts of my portfolio that are generating disappointing short-term results. But such things don’t cause me any regrets.
Instead, as I look back, my big financial regrets fall into four buckets:
Pound foolish.

THERE’S NO SUBJECT that gets me more worked up than market volatility—and especially the danger posed by high-frequency trading (HFT). Volatility has become part of the “new normal,” thanks to fundamental changes in how the market operates.
Remember the flash crash of 2010? I haven’t forgotten the unsettling events of May 6, 2010, when the Dow Jones Industrial Average dropped 600 points in just five minutes. For a few minutes, starting around 2:45 p.m.,

SENTENCES THAT BEGIN with “I can’t” drive me nuts—and I especially dislike the sentence, “I can’t save.”
“Pish-tosh,” I say.  Every household in America earning at least the median income can save for the future. If they try hard, many lower-income Americans could also save.
Of course, the amount saved will vary, but even small amounts can help over the long haul. If a household earning $40,000 a year can sock away enough to generate $300 or $400 in monthly retirement income to supplement whatever they get from Social Security,

MY FINANCIAL ADVISOR has been on a mission to reduce my investment costs. He’s been replacing my low-cost, broad-based index mutual funds with the exchange-traded fund (ETF) version. He believes this will improve my investment returns over the long run.
For instance, if you own Vanguard Total International Stock Index Fund—a mutual fund—you’re currently paying 0.11% in annual expenses. But Vanguard’s ETF alternative charges just 0.08%, equal to a savings of three cents a year for every $100 invested.

I WORKED IN THE investment department of three different insurance companies. But I never had any interest in buying a whole-life insurance policy. I knew term insurance was the best way to get the maximum death benefit for my premium dollars.
Instead, as a mutual fund manager, I was always more interested in investing in the stock market. (That said, I didn’t invest in the first mutual fund I managed. Why not? I didn’t want to pay the 7% “load”—the upfront sales commission.)
But my attitude toward whole-life insurance changed six years ago.

READERS KNOW I LOVE my baseball. There’s an old unwritten rule that, when a pitcher is working a perfect game, nobody talks to him. The position players leave the hurler alone since he needs to be “in the zone.” Fans grow more nervous as the game progresses and the ninth inning draws near. With each passing out, the prized perfect game comes closer into view.
I’m getting the same antsy feeling when it comes to highflying tech stocks.

DOES WEALTH BRING advantages? Yes—but it can also invite some unique challenges. Consider country music singer Kane Brown.
Shortly after moving into a new home, he went for a walk. He told his wife he’d be back in half an hour. But seven hours later, after getting lost, he ended up calling for help. What was unique about this episode is that, the entire time he was lost, Brown was on his own property.

TO MANAGE OUR MONEY better, often we don’t need to know more. Instead, we need to unlearn what we think we already know.
Here are just some of the things that, at various points in my 35-year investing career, I’ve thought I’ve known:

Which fund managers will outperform.
Which way the economy is headed.
What’s next for interest rates and share prices.
Whether the overall stock market is overvalued or not.
Which individual stocks will beat the market.