At the age of eight he was a keen swimmer, and for much of his life he taught local children to swim. Lambert's paternal uncle—like his father—also worked with animals, but as a professional gamekeeper; his maternal grandfather was a breeder of champion fighting cocks. Lambert grew up with a strong interest in field sports, and was particularly fond of otter hunting, fishing, shooting and horse racing. From his early teens, Lambert was a keen sportsman and by his late teens he was considered an expert in the breeding of hunting dogs.