Eternal Sunshine of the Spotless Mind (2004)

Joel Barish is emotionally withdrawn, and Clementine Kruczynski is his dysfunctional free-spirit girlfriend. They are attracted to each other despite their differences. After a fight, Clementine has her memories of their relationship erased. Devastated, Joel decides to have the same procedure but changes his mind. The film takes place in Joel's brain as he tries to preserve his memories while two techies attempt to erase them. The employees of the company performing the procedure have their own entanglements, which affect Joel and Clementine's relationship.