Train In The Distance Lyrics

Lyric discussion by EnochRoot1 

Cover art for Train In The Distance lyrics by Paul Simon

I would say that meaning of "the sound of the train in the distance" is defined in the lyric as "the thought that life could be better."

When you substitute the phrase into the chorus, you get:

Everybody loves the thought that life could be better. Everybody thinks it's true.

Which is really what the song is talking about. You live within the reality of your own life all the while looking into the future and thinking about how life would be if you could make it. As a child you might dream of your perfect wedding or what you will "be". As you get older you have the thoughts of what a perfect relationship might be even as you are in one that isn't quite perfect. You project yourself into the perfect home and family. People are often looking for what is going to happen instead of seeing the reality in front of them and accepting it and enjoying it for what it actually is - your life.

@EnochRoot1 - A very insightful comment. Thank you. It adds to my longtime appreciation of this song.