Cada quien ve la canción desde su punto de vista, yo la interpreto como que un hombre no sabe lo que tiene hasta que lo pierde, no sabe el amor que ella le dió hasta que lo perdió, quiere decir que ese hombre no la supo aprovechar no la supo hacer feliz cuando tenia tiempo, la canción habla de arrepentimiento de no saber aprovechar ese tiempo con ella y que cuando quizo recuperarla ya era tarde.

Espero haberte ayudado :)

Well you only need the light when it's burning low

Only miss the sun when it starts to snow

Only know your love her when you let her go

Only know you've been high when you're feeling low

Only hate the road when you're missin' home

Only know your love her when you've let her go

And you let her go

Staring at the bottom of your glass

Hoping one day you will make a dream last

The dreams come slow and goes so fast

You see her when you close your eyes

Maybe one day you will understand why

Everything you touch all it dies

But you only need the light when it's burning low

Only miss the sun when it starts to snow

Only know your lover when you've let her go

Only know you've been high when you're feeling low

Only hate the road when you're missin' home

Only know your lover when you've let her go

Staring at the ceiling in the dark

Same ol' empty feeling in your heart

Love comes slow and it goes so fast

Well you see her when you fall asleep

But to never to touch and never to keep

Because you loved her to much

And you dive too deep

Well you only need the light when it's burning low

Only miss the sun when it starts to snow

Only know your lover when you've let her go

Only know you've been high when you're feeling low

Only hate the road when you're missin' home

Only know your lover when you've let her go

And you let her go

Ooooo ooooo oooooo

And you let her go

Ooooooo ooooo ooooo

And will you let her go

Because you only need the light when it's burning low

Only miss the sun when it starts to snow

Only know your lover when you've let her go

Only know you've been high when you're feeling low

Only hate the road when you're missin' home

Only know your lover when you've let her go

And you let her go

Copia y pega esto en "Google Translate" y sabras de lo que habla :D