In some cases, it's clear that the speaker in a Paul Simon song is not, in fact, Simon himself. One example might be "Duncan," in which he states "Lincoln Duncan is my name." In other cases, it could go either way.
Here, Simon is very clear that this is an autobiographical effort. He announces that he is going to fast forward past "the boring parts," where he is a baby and even up through his college "graduation." The "bogus degree" is one in English. Considering he made his career as a writer, that may be unfair-- he might be one of the few to ever parlay that degree into a career at all!
He explains that he was a dreamer, not career driven: "I was more like a landlocked sailor/ Searching for the emerald sea."
The first thing of import that happens to him, that even invokes an interjection-- "Oh, my God"-- is his "first love," which "opens like a flower," then is suddenly much more intimidating: "A black bear" that "holds me in her sight and her power."
Then the metaphor shifts again. "But tricky skies, your eyes are true," could refer to the sky's metaphorical eyes, but the "you" could also to be listener, his first love. In this case, he thought the future was to be sunny with her, but the skies tricked him and instead brought forth foul weather. She did not trick him-- her eyes were "true"-- so fortune was what changed. This being autobiographical, I am going to go out on a limb and say this "first love" was Kathy, and the fortune that changed was his success.
"The future," it turned out brough both "beauty and sorrow," perhaps being both new loves, children, and recognition for his artistic efforts on the one hand, and the breakup with Garfunkel, his divorces, and other sorrows on the other.
So... does he regret his choice to leave Kathy in England and return to New York to pursue music? "Still, I wish that we could run away and live the life we used to/ If just for tonight and tomorrow." So he does wonder about it, but knows that his life now is what he would prefer. He is wise enough to know that, even if he had stayed, life would still have brought both "beauty and sorrow."
And then... we are at the present! But Simon is not resting on his many, many laurels. He still considers himself striving for better, newer heights: "I am walking up the face of the mountain/ Counting every step I climb."
As he climbs, he looks higher still: "Remembering the names of the constellations/ Forgotten is a long, long time." Perhaps this refers to his heroes, the "stars" he idolizes and idealizes, and feels that, even standing on his mountain, he will never ascend to those heights.
Plus, he may be out of time, or nearly so. He is aware of his age: "I’m in the valley of twilight." The next line, "Now I’m on the continental shelf," refers to the edge of a landmass that is usually underwater, before the land falls away and you are entirely in the ocean. Again, this is an image of near mortality.
In the last line, he perhaps summarizes his entire artistic career: "That’s me—/ I’m answering a question/ I am asking of myself." All of his songs are potential answers to the questions he has been pondering. Since he keep writing songs, perhaps he is trying to adjust to the fact that he may never know. At least he let us listen in.
Next Song: Father and Daughter