Mitch Robbins, portrayed by Billy Crystal, along with his best friends Phil Berquist and Ed Furillo, finds themselves grappling with a collective early mid-life crisis as they approach their 40s. In hopes of rekindling their adventurous spirits, Ed frequently proposes daring escapades, the latest being a risky venture of running with the bulls in Pampalona, Spain. This experience results in Mitch's rather embarrassing visit to the doctor, a precursor to the whirlwind of events that follows when Ed suggests they attempt target-parachute jumping.
As the days pass, Mitch wakes up to his 39th birthday, greeted by his mother's customary call recounting the frantic trip to the hospital during his birth. This morning takes a turn for the worse when his efforts at the radio station seem inadequate in his manager's eyes. Later, during a Career Day at his son's school, his profession garners lackluster reactions from the kids, leading him to reflect on the stark changes in his life as he laments aging.
That evening, Mitch's wife Barbara takes it upon herself to throw him a birthday party, inviting Phil, Ed, and their respective wives. The atmosphere becomes tense as Phil faces the wrath of his wife, Arlene, who mistreats him, ultimately resulting in him pretending to sleep to avoid confrontation. Meanwhile, Ed’s young girlfriend Kim is a striking contrast, being a lingerie model.
The festivities take a chaotic turn when Nancy, one of Phil's coworkers, arrives announcing that she believes Phil is the father of her unborn child. This revelation leads to a confrontation between Phil and Arlene, momentarily overshadowing the party celebrations. Barbara, noticing Mitch’s increasing despondency, expresses her concern that he, too, might stray in a search for purpose. Encouraged by her, Mitch ultimately agrees to join Phil and Ed on a two-week cattle drive in the southwest.
On the journey, they meet a diverse group of fellow riders, including Ben and Steve Jessup, two dentists, brothers Ira and Barry Shalowitz, and Bonnie Rayburn, seeking a fresh start post-divorce. As Mitch and his friends prepare for the rigors of the cattle drive, they suit up in ranch attire and practice their roping and riding skills. An altercation with two ranch hands, T.R. and Jeff, arises when they make unwanted advances towards Bonnie, leading to Mitch stepping in to defend her.
The tensions rise until an intimidating cowboy, Curly, intervenes, dramatically lassoing one of the ranchers into submission before commanding that they stop drinking. As the group gathers around the campfire that night, Mitch learns more about Curly's character, realizing he may not be as menacing as he seemed, despite an earlier spine-chilling encounter when Curly ominously remarked, >"I crap bigger n’ you."
As the cattle drive unfolds, Mitch and Curly form an unexpected bond, sharing thoughts on life and purpose during a night spent out in the wilderness. Curly eventually provides Mitch with insight about a secret of life—one that Mitch must decipher for himself. After an emotional moment involving the birth of a calf, whom Mitch names Norman, Curly's true nature is revealed, and Mitch begins to see a clearer path through the chaos of his life.
Tragedy strikes as Curly dies quietly while watching over the cattle, prompting the group to hold a solemn burial. Mitch and his friends share their most cherished and painful memories around the campfire, deepening their connections with one another. The drive is fraught with challenges, including reckless actions from T.R. and Jeff that force Mitch to take the reins and lead the herd himself, all the while wrestling with moral dilemmas regarding Norman the calf's fate.
As the journey concludes, the trio is left contemplating what lies ahead in their lives. Phil resolves to face the challenges of a new start post-divorce, Ed commits to his girlfriend's wishes for children, and Mitch finally grasps Curly’s metaphorical “one thing.”
Upon returning home, Mitch surprises Barbara by bringing Norman with him, ensuring the calf's safety from slaughter and solidifying his newfound understanding of what truly matters in life. The family sets off together, now led by Mitch's heartwarming decision to include their newfound companion, reflecting his personal growth as they head back home.
