To me this song is about the angst and unfamiliarity that comes with moving into unknown parts of life. The fact that no matter what, we can't stop a day from turning into a week, a year from turning into a decade, etc., can seem a little intimidating and disheartening. As humans we only know what we've experienced, and the idea of having to readjust and move forward without any regard for personal desire can be downright terrifying. While some people are just now "boarding the train" and beginning the human experience, others have been aboard for awhile and their "train ride" is gradually coming to a close as the natural cycle of life continues irrevocably.
To me this song is about the angst and unfamiliarity that comes with moving into unknown parts of life. The fact that no matter what, we can't stop a day from turning into a week, a year from turning into a decade, etc., can seem a little intimidating and disheartening. As humans we only know what we've experienced, and the idea of having to readjust and move forward without any regard for personal desire can be downright terrifying. While some people are just now "boarding the train" and beginning the human experience, others have been aboard for awhile and their "train ride" is gradually coming to a close as the natural cycle of life continues irrevocably.