A speaker walks down the street in the rain while strangers stare and wonder why he is alone and where his lover is. The poem slowly answers that question: the speaker loves someone who does not love him back, and that person is happy with somebody else. He also keeps his feelings secret, so the person he loves has no idea.
The speaker feels lonely and quietly hurt, but he doesn't fall apart. He recalls his mum's advice to make the best of what you have, and he accepts that she is right. The short, broken lines make the poem feel like a hesitant, held-back confession, and the repeated "They" and the crowd's question keep pressing on him. The rain suggests sadness, and it makes the image of someone else "playing in the rain" with his lover sting more. The mood is wistful, private, and resigned, ending with a sense that nobody around him will ever really understand.