In retirement, Rockefeller takes up a number of hobbies, including rediscovering his youthful love of bike riding, but in 1899 he finds the recreational passion that will remain with him for the rest of his life: golf. On the golf course, Rockefeller sheds his business persona and becomes downright affable. He also retreats more and more into open-air settings, preferring rural to urban life. He builds a home at Pocantico Hills on the Hudson River in New York, complete with a four-hole golf course.

Dr. Hamilton Biggar, a devotee of homeopathic medicine, becomes Rockefeller’s personal physician, and the titan begins thinking about living to 100. A robust man in his younger days, Rockefeller in 1893 develops alopecia, which causes hair loss. He appears to age overnight and tries many remedies, but ultimately settles for wigs. Cettie also has a variety of ailments that defy simple diagnosis. Bessie, meanwhile, suffers most of all. A mysterious illness, perhaps related to a stroke or heart condition, leads to the deterioration of her mind in 1903. In search of effective treatment, Bessie and Charles Strong sail for Europe the following year.

Edith, too, has a nervous disorder. Having married Harold McCormick, heir to the McCormick-reaper fortune, in 1895, Edith became something of a rebel and a wild-spending diva.