You can probably tell from the title that "To an Athlete Dying Young" is a bit of a downer. It is, surprise surprise, about an athlete who dies young.
The poem starts off cheerfully enough, with the speaker remembering when the athlete won a big race and everyone in town celebrated by carrying the winner around the marketplace. Sounds like good times, right?
We don't get to enjoy it very long, because the second stanza puts us at the athlete's funeral. Bummer. The stanza is basically an extended metaphor for death: the road of life, going "home," moving from the land of the living to the land of the dead—that kind of thing.
Things take an unexpected turn starting in stanza 3 and continuing through the poem's last stanza. The speaker starts listing why it's a good thing that the athlete died young. He makes some solid points, but in the end it's tough to argue the merits of a young person dying. Give this one a read and see what you think.