<p>Donald Arthur Nield died peacefully at Golden View Care, Cromwell, New Zealand, surrounded by family, on May 25, 2024, aged 89. He was the dearly loved husband of Rachel, cherished father and father-in-law of Cherry and Robert, Alex and Michael, Peter and Janice, and treasured Grandpa of Elizabeth, John, Charlotte, Frank, Rachel, and Michael. This is a scientific memoir written by D. A. Nield himself. In late March 2017 Don sent a copy of the document, below unedited, to Craig Simmons. This was in response to a discussion that Simmons had with Nield at that time when Simmons was preparing a historical note on the Elder Problem with John W. Elder. We can do no better than to publish Nield’s autobiographical note posthumously as is—in his own words. Nield himself called it “A scientific memoir.”</p> Graphical abstract <p></p>