For other people who have seen this movie here are the song and lyrics for
Clementine by Rick Mason
And a website to erase your own mind.
The movie quotes
The poem lines (207-210) the title is based on:
How happy is the blameless vestal's lot!
The world forgetting, by the world forgot.
Eternal sunshine of the spotless mind!
Each pray'r accepted, and each wish resign'd