Charles Simic : . . . Back in the ’70s, a woman stopped me on Second Avenue, in the 50s, on a hot summer day and asked me with tearful eyes to look for a pearl that she lost. That’s where the poem starts.
Interviewer: I’m guessing you never found the pearl.
Charles Simic: I did not. Are you kidding me? But I’m still looking for it as I walk around the streets of New York.
Paris Review interview (from here)