A lot of people think this song is about suicide, but I don't think that's actually the case. This song, I believe, is actually a love letter to someone who is dying but is scared to. The singer points out seasons, rain, and other things that have a natural end, but instead of trying to prolong their time, they simply continue on their due course. He also points out Romeo and Juliet, a couple so in love, they were not afraid to die if it meant being together. He says "we can be like they are", showing no fear of death when it comes. I remember reading somewhere that the number 40,000, was a rough estimate of how many people die each day, made by the songwriter, suicide being just one out of many causes. In the final verse, the perspective shifts, to a woman (or girl, age is not really specified here) who has reached the end of their life (came the last night sadness, and it was clear she couldn't go on). All of a sudden, Death Himself shows up, bringing with him a powerful gust of wind. He tells her not to be afraid of him, and she embraces him openly. At this point, she is now dead, and they both fly out the window, to the afterlife. The only time they look back to her former life is to say goodbye to it.

Sounds to me like Simon and Garfunkel are singing about religion in modern times. The protagonist is describing a dream where he is walking alone in his own halo of light, when another light shows up out of nowhere. In this other light, are other people. People who are saying nothing important, hearing nothing important, and singing nothing important. All the man hears from them is silence. When he tries to talk some sense into them, using phrasing that sounds like it came from the bible itself, they respond with nothing but a cold shoulder. Instead they turn to the other light, nothing more than a neon sign, and start worshipping it. And what does the sign say? "The words of the prophets are written on subway walls and tenement halls". Basic translation: the man plays Jesus in his dream, where he finds out he and his prophets have been replaced by materialism and graffiti.

Interesting biblical comparisons. I always personally felt this song was about growing up. The storyteller once imagined himself as a great king, living in his very own castle, ruling his very own kingdom. He felt he was greatly loved by his subjects, and greatly feared by his enemies. However, as he grew older, reality slowly began to set in; he eventually came to learn that life tends to suck, and that the castle he owned was nothing more than the kind a kid builds out of sand and saltwater. The wicked and wild wind would have been the moment when he hit puberty, as that is a time when most are torn between childhood and maturity. Everything is telling him to leave, right down to his subjects, who are now revolutionaries out for his blood. Now that he's a grown man, he's been hit by real life so many times he wishes to return to his fantasy kingdom, but is all too aware that he cannot, instead choosing to reminisce of the time he ruled the world.

I think this song is about an unfaithful person, who still loves the girl he cheated on. The second line in could be referencing the breakup song(s) Cry Me a River, which are sung from the perspective of a person who had just been cheated on. The singer feels little to no guilt about what he did, even pointing how insincere he can be, and subtle changes in one's own day-to-day appearance. This gives the girl a complex, to the point where she tries changing her image, and even loses the smile he adored so much, trying to meet what she feels are his standards. The second could be focusing in on this, by her "hiding" her pretty face behind makeup, in a attempt to look more appealing.