For years, I have wondered why, for some people, enough is never enough. For example, what could have possibly motivated Jon Corzine -- a respected former senator, governor and Wall Street big shot with hundreds of millions in the bank -- to take the top job at MF Global Holdings Ltd in the first place?

He was 63 years old, six months away from getting remarried. He was one of the few remaining high-profile Wall Street Democrats around, and an avid supporter of President Barack Obama. He was routinely mentioned as a possible successor to Treasury Secretary Timothy Geithner, if Obama were to win a second term.

Why couldn’t Corzine just enjoy his fortune, perhaps set up an eponymous foundation to do good works, bide his time and then use his connections to become Treasury secretary? He already had a cushy perch at Princeton University, where he invited any number of finance types to teach his class while he basked in their reflective glory. Life was good. (Disclosure: I once taught the class, although the amount of glory reflected is debatable.)

Instead, much to everyone’s surprise, in 2010 he decided to take on the thankless task of trying to revive MF Global, a second-rate futures dealer, at the request of his former Goldman Sachs Group Inc. colleague Christopher Flowers, whose private-equity firm had purchased a $150 million stake in MF Global in 2008.

An Odd Request

That Corzine would accede to Flowers’s request, even though Flowers had inadvertently helped to exacerbate the coup that toppled Corzine as co-chief executive officer at Goldman Sachs, was even odder. It’s hard not to think he was after some sort of personal and professional redemption at MF Global after his unceremonious departures from Goldman Sachs and the governor’s office.

You didn’t have to see the miserable spectacle of Corzine testifying before various Congressional committees this month to assume he now regrets his decision, even though his personal investment in MF Global was minor, around $3 million. What he has in spades is enough lawsuits and headaches -- to say nothing of possible criminal charges -- to last him the rest of his life. Why didn’t he just go quietly into the good night?

Last April, shortly before the verdict in the Raj Rajaratnam insider-trading trial, I spoke with a federal prosecutor, who compared white-collar criminals to drug lords he had prosecuted. “These guys had more money than God,” he said of the drug dealers. “They had so much money that they would have to bury millions of dollars in cash because there was no place else to put it. So their house, their yard, their huge farms would be full of these graves of money.” He continued: “For these guys it was always about who got the most amount of dope from Colombia to Mexico to the U.S. It was about saying -- when you’re there with all the other heads of the cartels -- ‘I’m the biggest guy. I got the biggest load.’”

Along the same lines, perhaps alpha males such as Corzine are often unable to choose the path that others see more clearly. Why did Robert Rubin, another of Corzine’s former Goldman Sachs partners and a man with a once-peerless reputation, take a job at Citigroup in 1999, after he left his position at Treasury secretary? Rubin’s decision, which netted him an extra $115 million or so -- on top of his Goldman Sachs fortune -- ended up badly tarnishing his image when it was revealed that he had a heavy hand in ramping up the risk-taking at Citigroup, causing it to almost go bankrupt and then need a government bailout.

Never Quit Trying

Why didn’t Rubin choose a route similar to that of Henry Paulson, another former Goldman Sachs chief executive officer and Treasury secretary, who had the good sense to set up a China-focused think tank in Chicago rather than return to Wall Street?

For that matter, why did the now 83-year-old Felix Rohatyn feel the need to return to Wall Street after his stint as President Bill Clinton’s ambassador to France? Rohatyn was already a legendary figure on Wall Street, but he couldn’t resist returning first as an advisor to Richard Fuld at now-defunct Lehman Brothers Holdings Inc. (oops!) and now as an advisor to Kenneth Jacobs at Lazard Ltd., the firm where Rohatyn established his reputation in the first place.

What is so wrong with retiring gracefully with one’s reputation largely intact? Why do these men feel such a need to constantly seek power and the limelight that often accompanies it, even knowing how often the final act turns sour? Perhaps the best explanation is one attributed to Pete Peterson, the 85-year-old billionaire co-founder of the Blackstone Group: “I don’t like it when the phone stops ringing.”

(William D. Cohan, a former investment banker and the author of “Money and Power: How Goldman Sachs Came to Rule the World,” is a Bloomberg View columnist. The opinions expressed are his own.)

To contact the writer of this article: William D. Cohan at wdcohan@yahoo.com.

To contact the editor responsible for this article: Tobin Harshaw at tharshaw@bloomberg.net.