The real wisdom here isn't about staying optimistic or open-minded—it's about acknowledging that your carefully constructed life might be interrupted by something your present self cannot yet conceive. Mary Oliver knows that the unimaginable doesn't announce itself; it arrives as a disruption, and we can either meet it with a cramped, defended heart or with some small space already prepared. When your teenager suddenly announces an unconventional career path, or a friendship deepens in ways you'd written off as impossible, that room becomes the difference between resentment and wonder. She's asking us to hold our certainties a bit more lightly.