Summary
This quote suggests that people often close themselves off from new possibilities or experiences as they age or grow older. It implies a resistance to change and a fear of the unknown, as symbolized by the setting sun. By shutting their doors, individuals choose to stay in their comfort zones and avoid venturing outside for new opportunities or perspectives. It highlights the tendency of humans to become more closed-minded and resistant to change as they age, instead of embracing the potential growth and learning that can come from embracing the unknown.