Who knew that chewing gum could symbolize the human condition? When the young hero of “Alexander and the Terrible, Horrible, No Good, Very Bad Day” wakes to find a wad of Wrigley’s (or some comparable substance) in his hair, he’s confronting an axiom that’s downright existential: Life doesn’t always go your way.

Good thing this inconvenient truth gets a hearty comic spin in Adventure Theatre’s staging of “Alexander,” the 1998 musical based on Judith Viorst’s children’s book. Moments after Alexander (Parker Drown) groggily greets the day, he discovers that he has misplaced the gum he was chewing as he fell asleep. Eyes widening in horror, he probes his mouth with his fingers, grimacing. No gum. He slithers under his bed and up the other side, but this search comes up empty, too. Now his fingers crawl through his hair, and by golly, you can almost feel that sticky clump matted to your own scalp.

The crisis is just one of the droll sequences in director Gail Humphries Mardirosian’s production, which teams Drown (a 2010 Helen Hayes Award winner for “Rent”) with Broadway veteran Sandy Bainum and an able supporting ensemble. Moving spryly around Douglas Clarke’s set — red jungle-gym-like tubing rearing over a red-and-purple tiled floor — the actors chronicle the small disasters of Alexander’s day: a falling out with his best friend; an after-school trip to the dentist; lima beans for dinner; and more. These catastrophes notwithstanding, Viorst’s book and lyrics, and Shelly Markham’s music, ultimately bring Alexander to the happy realization that tomorrow is full of possibility.

Fiddling with the hem of his shirt, letting his face flood with enthusiasm or disgust, Drown finds the charm in Alexander’s moodiness, and the other actors portraying young’uns capably channel squirmy childish energy. Bainum is appealingly quirky as Alexander’s bright-eyed, syrupy teacher, Mrs. Dickens, who strikes rhapsodic poses as her students display their artistic talents. (Bainum also depicts Alexander’s consoling mother.) Benjamin L. Horen, who plays Alexander’s dad and a goofily sinister dentist, strikes his funniest notes as a shoe salesman whose Brooklyn tough-guy accent belies an inner Elvis Presley.

Mardirosian and her creative team toss in amusing touches, such as the game of flashlight tag in the opening number; or the dreamlike montage of alarm clock sounds in an early scene (Brandon Roe is the sound designer); or the exotic copier (Ben Lurye and Kristen Garaffo) that makes R2-D2-like noises in ­Alexander’s father’s office. Kate ­Arnold Wernick’s inventive choreography includes a sole-clopping, limb-swinging segment that the performers execute while seated on the floor.

Adriana Diaz designed the costumes, including the stylized kangaroo and koala outfits that appear in “Australia,” a number expressing Alexander’s yen to move Down Under. In Australia, he knows, life and chewing gum are trouble-free.

Wren is a freelance writer.

Alexander and the Terrible, Horrible,No Good, Very Bad Day

based on the book by Judith Viorst; book and lyrics by Viorst; music, Shelly Markham. Directed by Gail Humphries Mardirosian; musical direction, Joshua Morgan; lighting design, Andrew Cissna; scenic artist, Sasha Goldstein. With

S. Lewis Feemster, Benjamin Gibson, Ashleigh King and Erika Grob. About one hour. Through April 9 at Adventure Theatre, 7300 MacArthur Blvd, Glen Echo. Call 301-634-2270 or visit www.adventuretheatre.org.