This song came from poetry written in Jim Morrison's notebooks. He wrote it after splitting up with his girlfriend, Mary Werbelow, in the summer of 1965. While the "Crystal Ship" is sometimes thought to represent drugs, Ken Rafferty from The Annotated Lyrics
makes this case:
This song has nothing to do with drugs and everything about Jim Morrison's heavy relationship with his first love, Mary Werbelow. As a poet, he did nothing more than use transparent images for his relation to the past. He (Jim Morrison) hasn't let go of her as evidenced in the first line, "Before you slip into unconsciousness, I'd like to have another kiss."
That means the protagonist had already left her in the physical realm, but has not left her subconsciously. The thought of her still burdens him and he just wants another kiss to somehow make it feel better.
"Another flashing chance at bliss, another kiss." Again, he cannot seem to let go of their love, their relationship, and how much she meant to him.
"The days are bright and filled with pain." He's moved on and is now doing very well as a singer/songwriter in a rock band in L.A., but he still has feelings for her and this song is his testament to her that he still has feelings for her.
"The time you ran was too insane." Jim was one to mock even his girlfriends- he would tease others, but mostly, he was testing them. This line very well could be a reference to a time he felt bad about verbally teasing her- knowing that it upset her.
"The streets are fields that never die, deliver me from reasons why, you'd rather cry, I'd rather fly." A simple line that confirms the end of the relationship and that the protagonist is willing to move on. The streets are fields are his memories, and because they are vague memories now, they also present a reason why he can forget.
And that last stanza confirms his growing popularity as a lead singer for a rock band with an ever-growing popularity. The beauty of it though is how he is saying to her that no matter how big he becomes, he will still think of her, and even call her, when he gets the chance.