Analysis: What's Up With the Title?
As you read, it seems like every line is saying "Nothing Gold Can Stay"—just in a different way each time. And that notion is pretty drastic. The title doesn't just say that most gold things don't last. It tells us that nothing, and we mean nothing, gold does.
You might look at a gold ring and think, "well, this has some staying power," and you'd be right. But this isn't the kind of gold our speaker is talking about. He means the gold of a spring day, of a child's smile, of anything in life that is perfect and happy, like the Garden of Eden or a beautiful sunrise.
The title and last line are general enough that we can think of this poem metaphorically. We can picture Michael Phelps looking at his gold medals in 2050 and missing the athleticism that faded into old age. Or an old movie star, looking in the mirror at her wrinkled face, missing the golden days of youth. We can see a teenager, packing up her bags to go to college, worried about student loans and whether or not she's going to make it academically, missing the days when she was a little kid, when mom and dad took care of everything.
So yes, gold the metal can actually stay gold for a while, but the golden things in life, the speaker suggests with this title, always seem to fade away.