Matthew Ricks' "Sunset" is only three lines long, but it moves from a small pleasure to a quiet sense of ending. The speaker begins casually, noticing that the clouds look pretty today. It's the kind of passing remark you might make to yourself while looking up at the sky. Then the sun goes down, and the tone shifts. The speaker says "I must go too," as if the end of the light is a signal that can't be ignored.
The poem doesn't say where the speaker is going or why. That gap is part of its effect. "Must" could suggest something as ordinary as heading home when it gets dark, or it could hint at something heavier, like a life coming to its close, since the poem links the speaker's departure so closely to the sun's. Either way, the mood is calm and a little wistful. There's no drama, just gentle acceptance. The speaker enjoyed the moment, and now it's over.