The stress of teaching makes it a job that one would expect to shorten lifespans. But until she died last month, the world's oldest person was Edna Parker, a 115-year-old former teacher in the US.
Born in 1893, she taught for several years and gained her teaching certificate. But as was usual at the time, she gave up her career when she married in 1913.
The Associated Press said the only advice she gave on how to live a long life was "more education".
Don Parker, her grandson, said before her death: "We don't know why she's lived so long. But she's never been a worrier and she's always been a thin person, so maybe that has something to do with it."
By coincidence, Mrs Parker lived in the same nursing home as Sandy Allen, the world's tallest woman, until she died in August.