Clayton M. Christensen, born on April 6, 1952 in Salt Lake City, USA, graduated with honors in economics from Brigham Young University in 1975 and received his MBA with distinction from Harvard Business School in 1979. He returned to Harvard Business School in 1992 to earn his DBA and was appointed as a professor in the General Management and Technology and Operations Management departments. He was the winner of the 1995 McKinsey Award.
Christensen is the originator of the concept of “disruptive technology”. His research and teaching focus on new product and technology development management, as well as how to develop markets for new technologies. His representative works include “The Innovator’s Dilemma” and “The Innovator’s Solution”.
Harvard University invited Christensen to explain to all students how to apply his management theory to their specific lives. When he was invited to speak, Christensen had already been diagnosed with cancer. Having experienced the darkest moments of life, he systematically summarized his insights into life and shared his experiences in achieving a happy and fulfilling life. It was because of his heartfelt effort that this speech was a great success, deeply moving the students present and sparking widespread discussion throughout society.

Developing a Life Strategy
In recent years, I have been observing the changes in the lives of my classmates from Harvard Business School. At class reunions, I have seen more and more unhappy people, divorces, and estranged relationships with their children. Why is this happening? It’s because when they decided how to allocate their time, talents, and energy, they didn’t firmly place their life goals at the top and center.
Harvard Business School admits 900 new students each year from around the world, and it’s surprising that a large number of them have never thought about their life goals. I told these students that Harvard Business School might be their last chance to deeply consider this question. If they think they will have time and energy to reflect on it later, then they are mistaken, as the burden of life only gets heavier: they have to pay their mortgage, work 70 hours a week, get married, and have children.
For me, having a clear life goal is crucial. After becoming a Rhodes Scholar, the pressure of my coursework became very heavy, equivalent to an additional year of study beyond normal Oxford standards. I decided to spend an hour every evening reading and reflecting, exploring why God put me in this world. But sticking to this goal was challenging, as spending an extra hour on this meant one less hour studying econometrics. Was it worth taking an hour out of my busy schedule to do this? I was conflicted, but I persisted and eventually found my life goal.
If I hadn’t done this and instead used that hour to learn the latest skills, such as studying the autocorrelation of regression analysis, then I would have wasted my life. Econometric tools are only used a few times a year, but achieving my life goal requires me to practice it every day. This is the most useful thing I have learned. Understanding your life goals is far more important than learning theories such as cost accounting, balanced scorecards, core competencies, disruptive innovation, 4P marketing, and Porter’s five forces.
Choosing a career and achieving success is only a tool to achieve life goals. But without a goal, life is inevitably empty and dull.
Effective Resource Allocation
How you allocate your resources, such as time, energy, and talent, determines your life strategy. I have a multitude of “careers” vying for these resources: I want to maintain a harmonious relationship with my spouse, raise excellent children, serve the community, strive for career success, and excel in church service. Given that my time, energy, and talent are extremely limited, how should I allocate my resources among these pursuits?
People who crave success often instinctively invest their extra time or energy into activities that offer short-term benefits. Our careers can provide the most concrete proof of our progress. For example, launching a product, completing a design, delivering a speech, making a deal, teaching a class, publishing a paper, receiving compensation, and being promoted are all visible achievements.
However, it is usually difficult to see the impact of time and energy invested in one’s spouse and children. Children make mistakes every day. It may not be until they are 20 years old that you can proudly say, “I raised an excellent child.” You can also neglect the relationship with your partner since the good relationship may not seem to deteriorate in normal days. Even though intimacy and love within the family are the most potent and long-lasting source of happiness, those who pursue excellence tend to unconsciously prioritize their careers and overlook their families.
If you study the roots of business disasters, you will often find a deliberate pursuit of instant gratification. If you apply the same perspective to personal life, you will also discover a similarly shocking and thought-provoking preference: the cherished initial aspirations become increasingly difficult to receive resource allocation.
Avoiding the mistake of “marginal cost”
Finance and economics teach us that when evaluating alternative investments, we should ignore sunk and fixed costs and instead base our decisions on the marginal costs and marginal benefits of each investment.
As we learned in our course, this idea can lead companies to rely too heavily on past successful experiences and overlook the need to build future capabilities.
If the future is just a repetition of the past, this approach might be reasonable. But if the future is different from history, this approach is flawed. In fact, the future is almost always changing. This theory explains the third question my students and I discussed: how to be an honest person and avoid getting into trouble.
When facing moral decisions in life, we often inadvertently apply the theory of marginal costs. A voice echoes in our brain, “I know we shouldn’t do this in principle, but the situation is special now, and it won’t hurt to break the rules just this once. It won’t matter.”
Doing “wrong things” with the lucky mentality of “just this once” seems to have very low marginal costs and therefore has an irresistible temptation. But it eventually devours you, making you forget where this road leads and how high the total cost of this choice is.
Let me tell you how I recognized the potential destructiveness of “just this once.” I was a member of the Oxford University basketball team. One year, we gave it our all and finished the entire season undefeated. My teammates on the team became my best friends for life. Later, we participated in a British basketball competition similar to the NCAA championship and eventually made it to the finals.

Inconveniently, the championship game was scheduled on a Sunday, and at the age of 16, I had made a promise to God to never play on Sundays. I explained the situation to my coach, but he was skeptical. My teammates also couldn’t believe it, considering I was the starting center for the team. They all came up to me saying, “You have to play. Can’t you make an exception, just this once?” As a devout believer, I went aside to pray, hoping God would tell me what to do. The revelation I received was clear: I could not break my promise. In the end, I did not play in the championship game.
From many perspectives, it was just a small decision, as I would have thousands of Sundays in my life. In theory, I could cross the line just this once and make an exception. But looking back, resisting the temptation of the “special circumstance” logic was one of the most important decisions of my life. Why? Because these “special circumstances” keep coming up in our lives. If I had made that exception that one time, I might have been unable to keep my promise to myself in the future.
The lesson I learned was that keeping 100% of promises is much easier than keeping 98% of them. If you always give in to the “just this once” temptation based on marginal cost analysis, you might end up like my friends who are now in jail, regretting their final outcome. You need to have your own convictions and draw a safety line for them.
Choose the appropriate scale for measuring your life.
In 2009, doctors found that I had cancer, and I thought I didn’t have much time left. Fortunately, it seems like I’ve escaped that fate now. But this experience has given me a new and profound understanding of my life.
Many copanies have profited greatly from my research, and I’m well aware of that. I know I’ve had a significant impact. But this illness made me realize that, for myself, those so-called significant impacts are actually insignificant. It’s quite interesting. This led me to a conclusion: God’s measure of me is not money but the specific people I have touched. I think this scale of life also applies to everyone.
My final advice is to think carefully about what standard you want to use to evaluate your life.