At the end of her new book, punk poet Patti Smith makes what is, especially in a memoir, an odd assertion. Invoking an oracular cowboy who pops up on occasion in this touching, weirdly wonderful reminiscence, Smith writes, " — Some things, the cowpoke breathed, we save for ourselves."

A proverb about reticence may appear to be a rationale for cloaking herself in a mystical mystery tour of her life, but Smith gets at a deeper point: how difficult it is to reveal in "a long string of slithering words" the complications, digressions, secret pain, fleeting joys, fluctuations and losses of what she calls "that lighthearted balloon, the world."

Smith opts out of the "story of my life, part 2." Readers anticipating a sequel to her National Book Award-winning "Just Kids" may be disappointed by "M Train," which travels a different path.

While "Kids" focused on the story of her lover and friend, photographer Robert Mapplethorpe, and their lives together as starving but ambitious pre-fame artists in New York City in the 1970s, "M Train" hardly concerns itself with biography, club dates, chronology or boldface names. Smith never mentions her own music, which includes 11 studio albums and countless concert tours of Europe, Asia and the United States.

Hopscotching the decades, Smith, 69, engages in reverie, mood pictures, patches of dreams, snatches from her ever-present notebooks, travelogue, cups of coffee, fetish objects, angels, poets, aging, jet lag and the worship of her literary heroes, from Jean Genet to Sylvia Plath.

Some hoped Smith would shed light on her "mystery years," roughly coinciding with the 1980s, when, after a string of influential albums in the mid to late 1970s ("Horses," "Wave," "Easter," "Radio Ethiopia") she married musician Fred "Sonic" Smith and more or less disappeared from view, moving to a town near Detroit. There, she and Smith had two children and lived in relative obscurity until his death from a heart attack in 1994. Smith returned to New York, and released more records and began touring again.

An oblique portrait of Fred Smith emerges in vignettes of a trip they take to a godforsaken Genet-related site in French Guiana. Patti and Fred at one point buy an old boat, but it proves unseaworthy, so they park it in their yard and sit in it and listen to baseball games on the radio. Fred Smith enjoys drinking beer at a local dive bar, while Patti drinks coffee. While Smith evinces a strong love for her husband, she writes almost nothing discursive about their courtship, marriage or children.

Some things she saves for herself. This doesn't come across as coyness, or whitewashing: Smith makes it clear from the start that this isn't that kind of book. Rather, Smith presents what is much more of an artist's interior thought memoir, "a sliver of personal revelation."

Her touchstones are other writers, not musicians. She travels, literally, to great lengths, to photograph an admired writer's grave, often taking a few stones as souvenirs after leaving behind tokens of her own.

Perhaps a bit drifty, dreamy and downbeat at times, "M Train" nonetheless has many lovely set pieces and an overall tone of moody exaltation akin to her music.

Claude Peck is a Star Tribune editor. On Twitter: @claudepeck