I Swear is a deeply heartfelt film, and if you finished watching it with one lingering question, it may have been what happened to John Davidson’s father. He leaves the family as John’s Tourette symptoms become harder for everyone to cope with, but the film never really returns to him. In real life, however, John did continue to see his father. His memoir reveals that the relationship remained complicated and distant rather than ending completely.
His father’s departure feels final in the movie
John’s father is part of his life early in I Swear. We see him supporting John’s football, but the family dynamic changes as John begins experiencing increasingly noticeable symptoms of Tourette syndrome.
At the time, neither John nor the people around him fully understand what is happening. His involuntary movements, sounds and outbursts put enormous pressure on everyday family life.
Eventually, John’s father leaves.
The film makes that moment feel particularly painful because there is very little closure afterward. Once the story moves forward, John is still living with his mother, while his father is simply no longer part of what viewers see.
There is no later reunion scene and no explanation of what their relationship became. It is easy, then, to come away believing that John never saw his father again.
His own account tells a more complicated story.
John Davidson did see his father again
In his memoir, I Swear: My Life With Tourette’s, John writes about the lasting effect those difficult years had on his family.
His parents' marriage did not survive the strain they experienced, and John's relationship with both of them became distant. But they did not disappear from his life altogether.
In his 2025 memoir, John says both of his parents were still alive when he wrote it. He also explains that he continued to see them and loved them, although they were not close.
That detail changes how the father's departure in I Swear can be understood.
Leaving the family home was a major break in John's childhood, but it was not the final moment between father and son. They still had contact later. What appears almost like a permanent disappearance in the movie was, in real life, a much more complicated family relationship that continued at a distance.
John also writes openly about the guilt he carried over what happened to his family. His memoir makes clear how deeply the breakdown of his parents' marriage affected him.
That does not mean John or his Tourette syndrome should be blamed for the marriage ending. It shows instead how much emotional weight he carried from those years, particularly at a time when Tourette syndrome was poorly understood by many of the people around him.
The missing detail also explains Dottie and Chris
Knowing that John still saw his parents makes another part of I Swear even more meaningful.
Dottie and Chris become enormously important people in his life. They offer him the patience, acceptance and stability that he had struggled to find elsewhere.
John's memoir shows how significant that relationship remained long after the period shown in the film. When he learned that he would receive an MBE, Dottie was the person he called, and he later wanted Dottie and Chris beside him for the ceremony.
That does not mean they simply replaced parents who had vanished. The reality was less tidy.
John still loved his biological parents and continued seeing them, but he was not particularly close to them. At the same time, Dottie and Chris became the people with whom he formed a much stronger sense of family and support.
It is a distinction the movie does not spend much time explaining because its focus is ultimately on John's life with Tourette syndrome and the people who helped him find acceptance.
Still, for anyone wondering why his father seems to disappear from I Swear, there is some real-life closure.
John Davidson did see his father again. Their relationship simply never returned to the kind of closeness viewers might hope for after watching his difficult teenage years. His memoir leaves us with something more human than a neat reconciliation: a family that remained connected, even after much of that closeness had been lost.