Phil wrote what may be the most on the nose
I started listening seriously to The Grateful Dead about 3 or 4 years ago, and the first album I got was American Beauty. At the time, my wife was spending lots of time visting her dad, who was dying of cancer, and Box of Rain seemed to me to be terribly apropos. I spent lots of time listening to it.
Then about a year ago, I learned that Box of Rain was written by Phil Lesh when his father was dying of cancer. He had worked out the whole song, including the vocal phrasing. Took it to Robert Hunter (one of the Dead's lyricists), who sat down and wrote the words "as fast as the pen would pull."
Well, they nailed it perfectly.
By the way, I learned about the history of the song from The Annotated Grateful Dead Lyrics site, whose location is left as an exercise for Google.