This picture is three days after the first bloom, the middle pedals and stamens have fallen off. The opportunity to pollinate the flowers is gone. The flowers on the right and left are fresh blooms. So while it is too late to pollinate the middle flowers, nature gives the plant more opportunities with later flowers. If the student missed pollinating the middle flowers, it is not too later to pollinate the fresh ones. In nature, timing determines whether the plant lives or dies. The more the opportunities are taken between the bee and flower, the more seeds will grow and the more nectar the bees will get to eat.