Enough.

That's the title of Vanguard founder John Bogle's fantastic book about measuring what counts in life.

The title, as Bogle explains, comes from a conversation between Kurt Vonnegut and novelist Joseph Heller, who are enjoying a party hosted by a billionaire hedge fund manager. Vonnegut points out that their wealthy host had made more money in one day than Heller ever made from his novel Catch-22. Heller responds: "Yes, but I have something he will never have: enough."

I thought about this line over the past week after two business stories, neither of them new, re-entered the media's spotlight.

The first is news that former McKinsey boss Rajat Gupta is being charged with insider trading.

If you're unaware of Gupta's story, here's the background: He was born in Calcutta to a journalist father and school teacher mother, both of whom died in his teens. He received an engineering degree from India's exceedingly competitive IIT school, moved to America, scored an MBA from Harvard, and in 1973 joined the McKinsey Co., one of the world's most prestigious consulting firms. He was named McKinsey's managing director -- the equivalent of CEO -- in 1994, a position he held until 2003. McKinsey isn't a public company, so we have no idea how much Gupta earned during his tenure. One has to assume, however, that he's worth, tens, probably hundreds, of millions of dollars.

He was successful. Rich. Respected. He had achieved more than most can dream of against incredible obstacles.

So what does he do in his golden years?

On the inside
After retiring from McKinsey, Gupta joined the board of directors of several organizations, including Goldman Sachs (NYSE: GS), Procter & Gamble (NYSE: PG), and American Airlines (NYSE: AMR). Public filings show he made as much as $2 million annually for his board work, which usually entails attending a few meetings a year.

Fast-forward to September 2008. As the financial system teetered on collapse, Goldman's board was summoned for a conference call to discuss Berkshire Hathaway's (NYSE: BRK-B) potential $5 billion lifeline investment. This was intensely secret information. And you have to remember how insane this week was. People really didn't know whether banks, including Goldman, would make it to the next day. Berkshire's investment was huge for Goldman. Anyway, according to the Securities and Exchange Commission, Gupta disconnected from the board's meeting and immediately called billionaire hedge fund manager Raj Rajaratnam from the same phone. Less than a minute later, Rajaratnam bought 175,000 Goldman shares. The SEC doesn't say what the two discussed on the call. You can guess. Rajaratnam netted nearly a $1 million profit the next day after the public learned of Berkshire's investment.

This is just one example of several. There were more meetings, more calls, more profits. The list goes on and on. The SEC claims Gupta's tips led to $17 million in gains for Rajaratnam. All of it insider trading, all of it very illegal.

Assuming the allegations are true (he denies the charges), Gupta could be in a heap of trouble. He'll probably be on the hook for millions in legal bills. His reputation is utterly shot. This from a guy who could have, and should have, spent retirement basking in his success while drinking a Corona on the beach.

Made off
The next story I've been thinking of comes from a recent New York Magazine interview with Bernie Madoff. You don't need an introduction. You know what he did.

What shocked me from the interview is the revelation that Madoff earned as much as $100 million a year from the legitimate part of his business -- market making -- before his Ponzi scheme ever began.

Think about that. Adjusted for inflation, Madoff was making the equivalent of $550,000 per day from legitimate sources. The guy was rolling. He had everything. Tons of money. Several homes. A family who adored him. Peers who idolized him -- the epitome of success. Yet he apparently wanted more so badly that it was worth tearing the throats out of his friends and family, spending the rest of his life in prison, and even sparking the death of his son, who committed suicide in December. It's spectacularly confusing.

Explain it to me
To a certain extent, theft -- white collar or otherwise -- makes sense for those who are truly desperate. Warren Buffett once noted that, despite his commitment to ethics, he wouldn't rule out holding up a store if he were broke, had two sick kids at home, and an empty kitchen. You do what you gotta do. It's why there's a correlation between poverty and crime.

But to quote Buffett again, who once ridiculed a different group of defunct financiers: "To make money they didn't have and didn't need, they risked what they did have and did need. And that's foolish. It is just plain foolish. If you risk something that is important to you for something that is unimportant to you, it just does not make any sense."

When people like Gupta and Madoff, who were already rich beyond belief, steal from others (indirectly or literally), you have to ask: What is the motive? Is it power? Maybe, but both already had layers of power before they misbehaved. Maybe they feel above the law? Could be, although Madoff mentioned before his arrest that, "In today's regulatory environment, it's virtually impossible to violate rules." Maybe they're just clinical sociopaths? Perhaps, but I'm not convinced it's that simple.

There's something else. For some reason, these people don't feel like they have enough. Many, many of us don't, even when we should. Why, I don't know. I'll ask for your help in a second.

Here's what we do know. In the field of positive psychology, the study of what motivates people and makes us happy, researchers are mostly in agreement: Money isn't the key to happiness. What really gives people meaning and happiness is a combination of four things: Control over what they're doing, progress in what they're pursuing, being connected with others, and being part of something they enjoy that's bigger than themselves.

Keep that in mind, and I want to ask you: What is enough? How much is enough money? How much is enough success? There's no right answer; everyone's different. Just share your thoughts in the comment section below.

Check back every Tuesday and Friday for Morgan Housel's columns on finance and economics.

Fool contributor Morgan Housel owns shares of Berkshire Hathaway and Procter & Gamble. Berkshire Hathaway is a Motley Fool Inside Value selection and a Motley Fool Stock Advisor recommendation. Procter & Gamble is a Motley Fool Income Investor selection. The Fool owns shares of Berkshire Hathaway. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.