John J. Brennan, chairman emeritus and senior advisor of the Vanguard group, Inc. he was elected to American express' board: as told to April Hall.

• Position: MY BOARD JOURNEY

What drew you to the American Express Board of Directors?

There were several things that encouraged me to consider joining the Amex board; I'll mention two. First, it is a truly exceptional company with excellent governance practices. Second, the company has an outstanding leader and leadership team along with an experienced and committed board--all of whom will be interesting, educational and enjoyable to work with.

What did you do to become an executive who is sought-after for boards? Did you network, build your personal brand, something else?

Really, none of the above. Most boards today have strategic processes for identifying the type of person, with certain personal and professional traits, they are trying to recruit. I know that's true where I am involved in board development roles.

What was your first job?

After college and before business school, I was very fortunate to work with a man named Bill McKenna at the New York Bank for Savings. I received a "mini-MBA" in leadership from him, while getting much exposure to the most senior people in the organization. I have thought of those lessons frequently throughout my career. A true gift.

What major mistakes did you make in your career that you learned from?

One lesson that I learned early on--and that I hear from many of my respected colleagues--is the importance of hiring the right person for the right role. Too often, the tendency is to hire the right experience (pejoratively speaking, the "right resume"), and that can prove to be problematic. The collateral lesson is that when you've made that mistake, you'll know it quickly and you should deal with it quickly. Such mistakes don't get better with time.

How has...