February 11, 1990. The gates of Victor Verster Prison opened and Nelson Mandela walked out into the sunlight of the Cape with Winnie's hand in his and his right fist raised.

The image circled the world in hours. The man who had been imprisoned for twenty-seven years — most of them on Robben Island, a bleak outcrop in Table Bay where the cold Atlantic current kept the temperature low and the humidity high and the limestone quarry blinded prisoners over the years with its reflected sunlight — was free. The fist was raised. The step was steady. His face showed no bitterness.

People who had seen photographs of him in 1964 at the time of his imprisonment looked at the photographs of 1990 and tried to understand how a man could look like that after twenty-seven years.

The night before his release, Mandela had done something that became known only later. He had thanked the prison warders and officials who had held him. Not in general — specifically. He had spoken to the men who had controlled his daily existence, who had the power to grant or withhold small dignities, who represented the system that had imprisoned him unjustly. He thanked them for what they had taught him about endurance. He told the ones who had treated him with whatever humanity they could manage within the system that he was grateful.

He said: I want to tell you something. I leave here with no bitterness. My freedom and your freedom cannot be separated.

Mandela had read Marcus Aurelius in prison. He had read the Stoics. He had read the Bhagavad Gita. He had, over twenty-seven years, arrived at the same recognition that every tradition that takes suffering seriously eventually arrives at: that bitterness is a second imprisonment, that the person who leaves captivity carrying resentment has not fully left, that the jailer who lives rent-free in your mind has been given a lease that only you can terminate. He did not forgive because the apartheid system deserved forgiveness. He forgave because he was not willing to spend the years of freedom in the prison that unforgiveness would have constructed inside him. As I walked out the door toward the gate that would lead to my freedom, I knew if I didn't leave my bitterness and hatred behind, I'd still be in prison. The walk out of the prison was not just a physical crossing. It was the completion of an inner work that had taken twenty-seven years.

He became president four years later. He appointed his former prosecutor as a minister. He had tea with the widow of Hendrik Verwoerd — the architect of apartheid. He wore the Springbok jersey to the 1995 Rugby World Cup final and the Afrikaner crowd that had never cheered for a black man in their lives chanted his name.

These were not political calculations. They were the expressions of a man who had decided, somewhere in the limestone quarry, that he would not let what had been done to him determine who he would be when it was over.

The fist that was raised at the gate was raised in triumph. The triumph was not over the jailers. It was over the second prison that bitterness would have built. He walked out carrying only what was his. Everything else he left at the gate.