This is because when Joel tries to resist the erasing, he hides Clementine in a memory in which his mother is singing that song. Dr. Merzwiak finds the memory and erases all of it, including Joel's memory of that song.
This is because when Joel tries to resist the erasing, he hides Clementine in a memory in which his mother is singing that song. Dr. Merzwiak finds the memory and erases all of it, including Joel's memory of that song.
Little Movie Moments 