For me I feel the song is looking back on a past love, the one person who you took for granted at the time who you just can not forgot no matter how much time goes on a happy memory which you did not appreciate at the time a happiness that has still not been bettered - there is no stone left the person has tried and tried to move on but can not move on or recapture there time they were living this happiness even though that person is no longer around they are everywhere in memories
For me I feel the song is looking back on a past love, the one person who you took for granted at the time who you just can not forgot no matter how much time goes on a happy memory which you did not appreciate at the time a happiness that has still not been bettered - there is no stone left the person has tried and tried to move on but can not move on or recapture there time they were living this happiness even though that person is no longer around they are everywhere in memories