Emmett Lathrop Brown is born into a wealthy family in Hill Valley. Details of his childhood are scarce, but it is known that he developed a deep fascination with science, particularly the works of Jules Verne. He likely benefited from a privileged upbringing, nurturing his intellectual curiosity and providing him with access to resources that fueled his early experiments and inventions.

Emmett legally changes his name to 'Doc' Brown, indicating a complete dedication to his scientific pursuits and a desire to be recognized within that field. This period marks a period of increased social isolation, immersing himself in complex theories and groundbreaking experiments, foreshadowing the intense focus that defines his life's work.

After slipping and hitting his head on his bathroom sink, Doc Brown has a vision – the key to time travel: the Flux Capacitor. This moment is the single most crucial point in Doc's life, providing him with the fundamental component needed to build a time machine. He dedicates the next 30 years of his life to perfecting the Flux Capacitor and building a time machine capable of harnessing its power.

After decades of tireless work and financial hardship, Doc successfully builds a time machine out of a DeLorean sports car, powered by plutonium. He enlists the help of Marty McFly to document his first time travel experiment. However, the experiment is cut short when Doc is seemingly killed by Libyan terrorists whom he swindled for the plutonium, sending Marty back to 1955.

In 1955, Marty finds a younger version of Doc to help him get back to 1985. Together they successfully send Marty back to 1985, altering history. He then learns that the Libyans will return and leaves Doc a letter warning him of his impending doom. Doc chooses to destroy the letter, deciding to let fate run its course.

The Libyans return to kill Doc and the original timeline plays out, except Doc is wearing a bullet-proof vest, which saves his life. Doc reveals to Marty that he read the letter anyway and spent the last 30 years living with the knowledge of his impending doom. The near-death experience cements his friendship with Marty and strengthens his resolve to use time travel for good. His choice to defy fate marks a turning point in his character.

Shortly after surviving the attack, Doc travels with Marty and Jennifer to the future (October 21, 2015) to prevent Marty's son from making a terrible mistake. This trip sets off a chain of events that involve multiple trips through time to different eras, including the Wild West, and further tests their friendship and Doc's ethical responsibilities regarding time travel.

After the DeLorean is struck by lightning, Doc is sent back to 1885, where he becomes a blacksmith and falls in love with schoolteacher Clara Clayton. He creates advanced inventions using limited resources. He ultimately decides to remain in the past with Clara, embracing a simpler life and starting a family, marking a significant shift in his priorities from scientific ambition to personal fulfillment.

At some point after settling in 1885, Doc builds another time machine (using a steam engine) and briefly returns to 1985 to visit Marty and show him his family: Clara and their two sons, Jules and Verne, named after Doc's favorite author. This return signifies a complete transformation for Doc, demonstrating that even a man obsessed with science can find happiness and fulfillment in family and love. He then embarks on further time-traveling adventures with his family.