In the year 1934, Donald Duck first made his appearance in the theaters of the world and soon shot to worldwide fame.
Ten years earlier, Mr and Mrs Duck of Scotland had a baby son. They called him Donald.
When he was ten, Donald Duck, the cartoon character, hit the screen. His poor namesake had to put up with all manner of jibes, jokes and comments for the rest of his life.
When young Donald (the human) grew up, he became a doctor. I think that we can safely say he was no quack.