Because the meaning of the music it represents to the people who think about whether we are sad or happy, but we think of those people, it makes us know his address alongside us.
The meaning of the song, it reflects the thinking of someone, no matter when we are sad or happy, but we thought it was someone we know he is always by our side.
Because the meaning of the song is the media to think of someone no matter when we are sad or joy is but when we think of that person, it makes us know he is beside us.