Total Recall

In Total Recall (1990), set in the year 2084, Douglas Quaid has recurrent dreams about Mars, where, as far as he knows, he has never been. At a holiday agency that implants artificial memories of visits to exotic places, Quaid signs up for a vacation as a secret agent to the Red Planet. It turns out, however, that he actually has been a secret agent on Mars. Another personality surfaces during implantation, and, for most of the movie, we cannot tell if the events we see are “reality” or programmed memories. A video of someone identical to Quaid tells him, “you are not you, you are me.”

Vidal, Fernando and Ortega, Francisco. Being Brains: Making the Cerebral Subject (Forms of Living)....

Total Recall on IMDb