When Eternal Sunshine of the Spotless Mind was released in 2004, it was acclaimed in part for its unique concept: A New York-based company called Lacuna peddles a service any heartsick ex-lover has dreamed of: Erase this person from my memory. Make me forget they ever existed. In the movie, memory manipulation is both compelling and repelling. And in real life…we’re closer than you might think. This is Mach at the Movies.