“Maga’s Daughter,” left, is a painting of Wyeth’s wife. “Braids,” right, depicts a woman he painted in secret.

We live our lives partially in secret: the secrets we keep to ourselves and the ones we ask others to keep for us. The long artistic life of Andrew Wyeth—born in 1917, painting by 15, dead at 91 in 2009—is a portrait of a man forever wrangling with secrets. In Andrew Wyeth: In Retrospect, the secrets are hidden in landscapes, anchored to weather-beaten rowboats moored in fallow fields, and etched in the bends of grass blades.

A bottomless grief for his father's traumatic death is perhaps Wyeth's earliest secret, one he explores through heavy symbolism in Winter 1946. Local boy Allan Lynch is seen running down a hill in rural Pennsylvania, toward unseen train tracks where he is about to discover the car with Wyeth's father and his young nephew's mangled bodies pressed inside. The earflaps of Lynch's aviator-style hat and the coattails of his hand-me-down oversized soldier's jacket fly askew as his shadow lengthens behind him.

Wyeth's chosen medium of tempera—handmade daily from egg yolk and pigment—made for a longer process and more intimate engagement with his models. His muses included a handful of other locals in Pennsylvania, where he wintered, and in Maine, where he summered, including Christina Olson, famously of Christina's World (sadly not on view).

In the early 1970s, Wyeth embarked on his secret paintings of Helga Testorf. Wyeth and Testorf's relationship over 14 years, 45 paintings, and 200 drawings has lent itself to endless speculation. What we do know is Wyeth found it necessary to hide the labor of these secret paintings from his wife, Betsy, by working on bigger, more ambitious paintings simultaneously. In one nude portrait of Helga, she sits on a stool by an open window, her body facing the artist but her head turned demurely to the right. Despite Wyeth's claim that the figure was a composite of many women, his wife seemed to have sensed otherwise and named the painting Lovers.

Of Wyeth's many women, there are very few paintings of Betsy. In Maga's Daughter, Betsy wears a flat antique riding hat and her hair is perfectly styled. Her look is that of an all-knowing matriarch, never out of control. It is a stark contrast with Braids, a portrait of Helga with loose, messy hair whose introspective gaze was undoubtedly part of what attracted Wyeth to her.

It is Wyeth's last painting—on view at his memorial and exhibited here for the public for the first time—that can be seen as a tacit acknowledgement of Betsy as the keeper of all his secrets. A white clapboard sailing loft sits high atop a hill. In the foreground, a sloop cuts hurriedly to the left, just about to sail out of the frame. The boat and the building were both gifts from Betsy to her husband, in the hopes he'd spend more time with her on her island than on the other side of the harbor where his preferred muses were. As with all his other works, the painter and his wife agreed on the title: Goodbye.