This song is about yearning in the twilight - that most romantic time. It is about hoping that someone that you still think about is still thinking about you. It is the regret of an older person - maybe the speaker saw problems that had no easy solution - was one of the lovers already married? Whatever, the speaker took what was seen as the high road and released the other person. All that is left is the longing and regret and the hope that the memory of the other person also regrets and longs for the speaker. It is as if the speaker wants to catch and this time keep the lover in the net of memory. It reminds me of that Yeats poem "When you are old and sitting by the fire take down this book etc." Memory is a kind of balm - a bitter-sweet mixture of time's erosions and hope's unfailing solace.