Imagine wanting to be an artist all your life — or An Artist, as historian Nell Painter puts it in "Old in Art School: A Memoir of Starting Over" — and when you finally get to art school, this is what you hear from one of your teachers: "You may show your work. You may have a gallery. You may sell your work. You may have collectors. But you will never be an artist."

Now imagine how that sounds to an accomplished black woman — professor of U.S. history, bestselling author, recipient of honorary degrees — who, despite her achievements, was nonetheless accustomed to such slights as having white academics ignore her at university events when she wasn't wearing her Princeton badge.

None of this daunted her, however. At 64, she retired from Princeton and pursued her artistic ambitions, first by earning a bachelor's degree from Rutgers University's Mason Gross School of the Arts near her home in Newark, N.J., and then an MFA from the Rhode Island School of Design.

In this frank book, Painter highlights the myriad challenges she faced, starting with her age, which, more than her race, was "my defining characteristic, of how others saw me as a demand to see myself through their eyes."

Then there was her realization that she had an old-fashioned idea of what constituted art. "My lying twentieth-century eyes favored craft, clarity, skill, narrative, and meaning," but her 21st-century classmates and teachers taught her to embrace the "DIY aesthetic," the "drips, smudges, and what in the twentieth century would have been considered mistakes needing to be cleaned up."

This is a story of a woman determined to redefine herself, a task made more difficult by the casual racism she faced in school and the increasing frailty of her parents, both approaching age 90, back home in Oakland, Calif.

Painter's tone can be self-congratulatory, but she tells an inspiring tale of an older person pursuing a long delayed passion. And she has an entertaining writing style, as when, after having stated that gallery representation "is the main criterion for who counts as An Artist," she answers an age-old question: "What is art? Art is what's in galleries. Now you know."

"I am a wise old person, not a hot young artist, not a young anybody with a young anybody's future before me," Painter, now 75, writes. But that hasn't stopped her from creating art. The lesson of this memoir may be obvious, but it bears repeating: You're never too old to tell your stories, or to find new ways of sharing them.

Michael Magras is a member of the National Book Critics Circle. His work has appeared in the Houston Chronicle, Pittsburgh Post-Gazette and Newsday.

Old in Art School
By: Nell Painter.
Publisher: Counterpoint, 331 pages, $26