Last week, Bernie Mac, the actor and comedian, died of pneumonia in his home town of Chicago at the age of 50. While I wasn't a big fan of Mac's comedy, I couldn't help but see in his obituaries the enormous determination and sacrifice that must have gone in to developing his extraordinarily successful career.

Reading Mac's life story, I was struck by how clearly he exemplified all four of the behaviors and attitudes that my co-author, Russ Alan Prince, and I describe in our book, The Middle-Class Millionaire. These attributes -- which we call "Millionaire Intelligence" -- are prevalent in the lives of most successful, self-made individuals, and I was reminded in Mac's story that these very same tools can be used to create a successful business or develop a craft and rise to the top of your game, as he did.

The four attributes of "Millionaire Intelligence" are:

Hard Work: Before finally catching the attention of some of comedy's biggest names, Mac (born Bernard Jeffrey McCullough) could be found doing double duty in some of Chicago's toughest clubs and comedy venues. "When I started in the clubs, I had to work places where didn't nobody else want to work," he told the Washington Post -- including clubs where street gangs and motorcycle gangs hung out.

While putting his neck on the line comedically night after night, he managed to make ends meet and provide for his family as a janitor, a mover, a school bus driver, and by working at a General Motors plant, according to The New York Times obituary.

Perseverance in the face of adversity: He lost his mother to cancer when he was 16 and was raised by his grandmother on Chicago's South Side. Both his brothers died, one in infancy, the other in his twenties. To explain why he chose comedy as the focus of his talents, The Times obituary quoted him as saying that Bill Cosby could turn his mother's tears into laughter and "when I saw her laughing, I told her that I was going to be a comedian so she'd never cry again."

Networking: Mac was "discovered" and received early support from comedy luminaries such as Redd Foxx and Spike Lee. They were among the influentials who championed Mac and brought him onto bigger stages, culminating in a career on the large and small screens that won him awards, fans, and international recognition. If Mac's story is like the others I've studied, those encounters with individuals who could help him achieve his longterm dreams came about through diligence and taking risks.

Enlightened Self-Interest: When Mac was voted "class clown" in high school, he turned the honor down because he already understood the difference between clowning around and being a professional comedian. According the Times, he said, "I'm a comedian. I'm not a clown." Mac pursued and achieved great success and, in observing the path he took, one can only conclude that he had his sights set on such success early on. Every decision he made, every chance he took, was designed to help him get closer to reaching this lofty goal. Mac scaled the heights of his chosen profession and did so against great odds. One can only do that through single-mindedness and passion.

Bernie Mac knew that making people laugh was more than just clowning around, it was serious business.