I heard this on Radio 4 and thought of our struggle to convince doctors about thyroid issues.
Max Karl Ernst Ludwig Planck (23 April 1858 – 4 October 1947) is the originator of modern quantum theories and one of the most important German physicists of the late 19th and early 20th centuries, winning the Nobel Prize in Physics in 1918.
"A new scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die, and a new generation grows up that is familiar with it."
or paraphrased variants:
"Truth never triumphs — its opponents just die out."
"Science advances one funeral at a time."