Metallica wrote this after their equipment was stolen in early '84 and they had to start all over again. More specifically, James Hetfield wrote the lyrics in response to one of his amps being stolen. Not only was this amp his favorite, but it was also the first amp he ever owned so it had a lot of sentimental value to him. The song is about losing everything and wondering if it is worth going on.
The song's title is never mentioned in the lyrics, although the Metallica song "The Memory Remains" on their 1997 album Reload does have "fade to black" in the lyrics.