Lyric discussion by kae23 

I don't see this as a song about a relationship. To me it sounds more like people who might be, or have, contemplated suicide:

And he was sitting by the swimming pool But he was scared, cause it wasn't his time, it wasn't his chance. (He might be thinking of drowning/killing himself, but he has second thoughts, reflecting that it might not be his time to go)

Getting olders not been on my plans But its never late, its never late enough for me to stay (She never planned on living long enough reach an older age, but if she had a good enough reason to live longer she'd consider it)

.... And all the cigarettes that I have never smoked. And all the letters that I have never sent (Sounds like she is looking back on all the things she hasn't done, maybe things she might regret)

I like this interpretation, this is exactly how I see it, being one who has thought of things this way.

And all the cigarettes that I have never smoked, is like an analogy for suicide, as cigarettes are a form of long-term suicide plan.

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