Patton was a fervent believer in reincarnation, and more specifically, that he had lived many lives as a warrior throughout history, and was quite unabashed about sharing it. Although the famous scene in 1970s Patton where he tells Bradley about his involvement in a battle for an ancient Carthaginian city is fictional, it draws on very real ones for inspiration.

In a real situation, which I believe was included in the film, when Sir Harold Alexander remarked to him that he would have been well suited to command under Napoleon, Patton simply replied that he had been. Hardly a one off remark either, as upon crossing the Danube in 1945, for instance, he waxed nostalgically about Napoleon's attack on Ratisbon, which was near-by their crossing point, in the first person plural of "our storming-day."

The 19th century was not his only haunt either. the aforementioned scene with Bradley is fictional, but the poem he recites is very real, written by him in 1922 and detailing his fight through time:

Through the travail of the ages,
Midst the pomp and toil of war
Have I fought and strove and perished
Countless times upon this star.

It goes on to make mention of everything from hunting mammoth in prehistoric times, through being the Roman legionnaire who "stabbed our Savior in his sacred helpless side", detours to dying from a lance wound at Crecy, and of course again touching on Napoleonic times. [The entire piece can be read in Parameters. It is perhaps the best illustration of his vision of himself as an eternal warrior destined for battle, and while only a small part of his persona, it is one that is fairly outsize in his remembrance to history.

Sources

Axelrod, Alan. Patton: A Biography. St. Martin's Griffin, 2015.

Daniel, J. Furman. Patton: Battling with History. University of Missouri Press, 2020

Nye, Roger H. "Whence Patton's Military Genius?." Parameters 21, no. 4 (1991): 60.