Joel Barish, a man who is informed that his ex-girlfriend Clementine has had her memories of their relationship erased from her brain via an experimental procedure performed by Dr. Mierzwiak. However, as he watches his memories of her fade away, he realizes that he still loves her, and may be too late to correct his mistake.
It's a very Kaufmanesque narrative experiment, technically ingenious and sophisticated. It also looks like some lost comedy idea by Philip K Dick; you could call this film We Can Forget It for You Retail.
Works marvel after marvel in expressing the bewildering beauty and existential horror of being trapped inside one's own addled mind, and in allegorising the self-preserving amnesia of a broken but hopeful heart.