In 1983, a 12-year-old boy named John Davidson, who lives with his working-class family in Galashiels, Scotland, is eager to chase his dream of becoming a footballer. He starts his journey at Galashiels Academy, but on the morning a football scout is scheduled to evaluate his goalkeeping skills, John is unexpectedly struck by sudden tics and uncontrollable outbursts of swearing while at school. This results in severe punishment from his head teacher, who disciplines him by whipping his hand with a belt, leading to a dismal performance during the scout’s visit due to John’s pain.
As John's condition continues to create chaos, the head teacher suggests that he seek a transfer to another school. A turning point occurs at the dinner table when, after an incident where he spits at his family, John is forbidden from dining with them, being relegated to eating alone in front of the fireplace. This situation significantly affects his parents’ marriage, ultimately leading to John's father leaving home. Crushed by these events, John attempts to take his own life by walking into a river but is saved and awakens in a hospital.
Fast forward to 1996, at age 25, John is still living with his mother Heather, who is struggling with the reality of his diagnosis of Tourette syndrome, a condition that remains uncurable. A chance encounter reuniting John with his childhood friend, Murray, presents new challenges. Murray has returned from Australia, burdened by the news that his mother, Dottie, a mental health nurse, has been diagnosed with terminal liver cancer, and she has only six months to live. Dottie warmly welcomes John, sensing his discomfort and concern over his medication. Despite Heather's reservations, Dottie convinces John to stay with their family and helps him secure a job interview at the local community centre.
During a job orientation, John meets Tommy, the elderly caretaker, who surprises him with his calm demeanor during John’s tics, except for a moment when John unintentionally strikes Tommy's dog, making him fear he may have ruined his chances. Nonetheless, the support from Murray’s family helps John land the caretaker assistant role, and blessings follow when it's discovered that Dottie's health issue is not as severe as anticipated.
Excited about his new job, John faces a setback when he's assaulted outside after a tic leads him to accidentally call a woman derogatory names. Dottie remains a pillar of support during his recovery in the hospital, ensuring him that his job will still be available upon his return. John's relationship with Tommy grows, with Tommy mentoring and guiding him through work. A bar incident leads to John's involvement in a trial where he struggles to maintain decorum, swearing in the presence of the judge. Thankfully, Tommy defends him, and John is acquitted.
Tragically, after attending Tommy’s funeral following his unexpected death from a heart attack, John fears losing his job, but instead, he's reaffirmed of his position. In a twist of fate, John is also referred to a family seeking help for their daughter suffering from Tourette's, which leads him to create workshops at the community centre and tackle public speaking engagements to promote awareness about the condition. His efforts culminate in him receiving an MBE from the Queen in 2019. This significant moment allows John to reconcile with his mother, where they exchange apologies and forge a deeper connection over his achievements.
By 2023, John partners with researchers at the University of Nottingham to trial a non-invasive median nerve stimulation device, designed to alleviate his tics. This innovation empowers him enough to successfully engage in conversation on a train journey home, marking a milestone in his journey to greater confidence and independence. The film concludes with real-life footage of John Davidson, who has been the subject of various BBC documentaries—including "John's Not Mad"—along with a closing message that emphasizes the vital need for societal awareness in managing Tourette's syndrome.
