Nelson Mandela’s relationship with the Clinton family reflected genuine friendship from an early stage, stemming from their matching personalities and the Clintons’ swift intellect, according to an insider account.

“It’s quite noticeable how broad their view was of the world, how informed they all are — all three of them — about all details of the very small countries around the world,” Zelda la Grange, the woman who served as Mandela’s private secretary from 1997 until his death, said in an interview about her new memoir, “Good Morning, Mr. Mandela.”

In recounting his memory of Mandela, after his passing, Bill Clinton called him the “only free man I ever knew.” However, Clinton also alluded to “disagreements, which, believe it or not, occasionally occurred.” But Clinton and Mandela fundamentally agreed on many issues surrounding freedom and equality, and found propinquity in teasing each other in playful amusement.

“Madiba was always ragging me because it was my job when I was president to rag him about being friends with Gaddafi and Castro,” Clinton jokingly recounted.

The story begins with Bill at a charity auction - when he is informed by the hosting organization that Mandela had expressly desired Clinton bid on a certain item, not specifically saying what it was - leaving Clinton with the impression that he would know what Mandela was referring to when he saw it.

The auction started and continued with items announced for bid one after the next, but none of the items offered for sale bared any significance to Clinton - in reference to his relationship with Mandela, until finally a fine-quality Cuban rum was announced for bid. Clinton immediately got the joke.

“I think I paid $11,000 for that bottle of rum,” Clinton said laughing, without regard for the fact he could not even bring it back with him to the United States, given the embargo imposed on Cuban goods. Originally enacted in 1958, the United States - Cuba trade embargo has been one of the most enduring embargoes in modern history.

In 1999, President Bill Clinton expanded the trade embargo by disallowing foreign subsidiaries of U.S. companies to trade with Cuba in any capacity. However in 2000, Clinton did authorize the sale of humanitarian aid to Cuba.

As for the $11,000 rum, Clinton "didn’t have the capacity to consume it all before returning to the United States.” Furthermore, Clinton never mentioned what he did with the item he was successful in obtaining. The rum was ironically a gift to Madiba from Cuban President, and longstanding U.S. adversary, Fidel Castro.

Still, throughout Mandela's life and their friendship, Clinton struggled to understand one unusual aspect of Mandela's story that still puzzles him to this day.

"How did he go through all this and come out a better man than he went in?” Clinton often found himself pondering, once finally asking Mandela: “Tell me the truth - when you were walking to freedom - didn't you hate them again?” Clinton Continued, “What I loved about him, because he was not saint of course, he said: 'Of course I did, but I got over it in three seconds.'"

Mandela, wise beyond his years, knew that if he continued to carry the burden of hatred in his heart he would forever remain a prisoner. - "'I wanted to be free so I let it go.’”

“As a friend, Madiba was to people one-on-one the same way he was as leader and even to his adversaries who he put in government,” Clinton said. “He lived as he governed.”

“We cannot allow his legacy, his memory, his meaning, to drift into the history books, to become a distant memory,” Clinton said. “He must be as real to people who never knew him, as real to children who cannot remember him, as real to grandchildren who are not yet born as he is to those of us who loved him.”

Neil Degrasse Tyson leads Sea and Space Exploration Summit:    • Neil deGrasse Tyson, Hillary Clinton ...