This Doctor Who Lived to 105 Believed That for a Long Life, You Shouldn't Retire Dr. Shigeaki Hinohara believed that work was key for longevity.

To live a long life, work forever. At least, that's what one of Japan's leading doctors believed -- and he was his own proof.

Before his death on July 18, 105-year-old Dr. Shigeaki Hinohara was a practicing physician, a chairman of St. Luke's International University and the honorary president of St. Luke's International Hospital. Up until a few months before his death, Hinohara was active in the medical community -- treating patients, taking new appointments and working up to 18 hours a day.

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Often credited as a major contributor to the foundations of Japanese medicine and in positioning Japan as a world leader in life expectancy, Hinohara held a number of beliefs for healthy living and longevity. And one of his main ones was: "Don't retire. And if you must, retire much later than age 65," he told the Japan Times.

Maybe we should listen to the wise words of Hinohara, who believed that because the average life expectancy of Japanese people reached 84 years as of 2015, then the retirement age should be pushed back too, because work is what helps keep people going. At least that was the case for Hinohara, whose career, in a way, kept him living.

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Janit Kawaguchi, a Japan Times journalist who considered Hinohara a mentor, said, "He believed that life is all about contribution, so he had this incredible drive to help people, to wake up early in the morning and do something wonderful for other people. This is what was driving him and what kept him living."

On top of working for as long as possible, Hinohara also preached other guidelines for a long life, including having fun, always taking the stairs, asking your doctor questions and unsurprisingly, not being overweight.