The speaker looks back on a past self and describes it in fragments, almost as if the memory has loosened and drifted. "I was a rose / or something else loose" is a playful, slightly slippery line: a rose is beautiful and traditional, but "loose" suggests petals falling, or maybe someone carefree, even a little improper. The speaker can't quite settle on what they were, and that vagueness is part of the feeling.
Then the poem shifts to "the morning paper / talk of sin." Something ordinary and daily sits beside something heavy and moral. The poem doesn't say whether the speaker is troubled by that talk or simply amused by it. "A little over" could mean the speaker was slightly above it all, or that something was slightly finished.
The mood is wistful and wry, with a light touch. The title, "Bygone," suggests the speaker is watching a former self fade, and the short, unfinished lines leave that sense of fading hanging in the air.