Berjon was born in St Pierre de Vaise, a commune near Lyon, to the son of a butcher, and he first studied drawing with the local sculptor Antoine-Michel Perrache (1726–1779).
His early history is not clear; according to his uncorroborated biographer J. Gaubin, he may have studied medicine or a religious vocation, learning flower painting during his novitiate.
He visited Paris often in the early 1790s and moved there in 1794, becoming a friend of Jean-Baptiste Jacques Augustin (1759–1832), a painter of miniatures, and of Claude-Jean-Baptiste Hoin (1750–1817), a portraitist.
His temperament probably put him in conflict with the school's administration; he was known for his stubbornness, and some contemporaries viewed him as egotistical, a characterization that remained throughout his life.
The skeletal shark's head and the seashells are at first incongruous, but show that Berjon has adapted his style to the era of the Enlightenment, diversifying the subject matter to represent the age's new sense of nature.