Bill Clinton jokes that he felt lost when he first returned to private life in 2001, after his two terms as president, because people no longer played “Hail to the Chief” when he walked into a room. But what he found – chronicled in his new book, “Citizen: My Life After the White House,” published Tuesday by Knopf – was that philanthropy has allowed him to continue making changes in the world to help others. “I had a good time doing it,” Clinton told The Associated Press in a phone interview.

“I am also gratified that so many people — if you go and make a rational case for doing something – will go along even though it didn’t seem to be in their immediate financial interest.” That method established a market for generic manufacturers of HIV/AIDS treatments that lowered the price of the drugs enough to make them available to countries around the world. Lower prices, now negotiated with drug manufacturers through what has become known as the Clinton Health Access Initiative, help provide HIV/AIDS treatments to nearly 1 million children around the world and have saved the lives of tens of millions of people.

It’s one of many successes the Clinton Foundation and its numerous campaigns — including the Clinton Global Initiative which gathers political, business and philanthropic leaders in New York each year during United Nations General Assembly week — have managed in the past two decades that Clinton writes about in “Citizen.” He also recounts .