The two alternatives left then to us were either to emigrate to the United States, or to pursue some activity that needed neither support nor connection with the outside Aryan world where we lived. My family chose this second alternative. I then decided to build a small research unit at home and installed it in my bedroom. My inspiration was a 1934 article by Viktor Hamburger reporting on the effects of limb extirpation in chick embryos. My project had barely started when Giuseppe Levi, who had escaped from Belgium invaded by Nazis, returned to Turin and joined me, thus becoming, to my great pride, my first and only assistant.

I had two options. One was to remain silent and wait to be killed. And the second was to speak up and then be killed. I chose the second one. I decided to speak up.

I unfortunately contracted tuberculosis at the age of sixteen and had to take a two-year break and receive treatment at home before I resumed my study at the private Ningbo Xiaoshi High School (1948–1950) and Ningbo High School (1950–1951). This experience led me to make a decision to choose medical research for my advanced education and career – if I could learn and have (medical) skills, I could not only keep myself healthy but also cure many other patients.

God has never let me down. He’s a key factor in guiding my decisions and feeling safe within them. My wife and I suffered three miscarriages, one of them quite late in the pregnancy. Without faith, we would have retreated into our own corners to lick our wounds, but our love increased.

Scooping ice cream is tougher than it looks. … Rows and rows of rock-hard ice cream can be brutal on the wrists. … I was less interested in what the job meant for my future and more concerned about what it meant for my jump shot.

I would end every night reading these ten letters. It made the numbers and the policies very concrete and very specific. And I was reminded that the choices we were making were affecting millions of people. I found that to be very useful.

And democracy requires compromise, even when you are 100 percent right. This is hard to explain sometimes. You can be completely right, and you still are going to have to engage folks who disagree with you. If you think that the only way forward is to be as uncompromising as possible, you will feel good about yourself, you will enjoy a certain moral purity, but you're not going to get what you want.

One of the things that Michelle and I are proud of is that we came through the White House with our souls intact. Everybody has heard: Power corrupts. I do think if you are placed in such an artificial situation, and your office has great importance, there is a tendency for people to want to please you. To not be as honest with you. We fought against that.

People ask me sometimes, who inspires you, Mr. President? Those quiet heroes all across this country -- some of your parents and grandparents who are sitting here -- no fanfare, no articles written about them, they just persevere. They just do their jobs. They meet their responsibilities. They don't quit. I'm only here because of them. They may not have set out to change the world, but in small, important ways, they did. They certainly changed mine.

And finally, change requires more than just speaking out -- it requires listening, as well. In particular, it requires listening to those with whom you disagree, and being prepared to compromise. When I was a state senator, I helped pass Illinois's first racial profiling law, and one of the first laws in the nation requiring the videotaping of confessions in capital cases. And we were successful because, early on, I engaged law enforcement.