This quote essentially means that opportunities often only present themselves once and it’s important to seize them when they do. The imagery of Fortune being bald at the back signifies that once she has passed, there’s nothing left to grab onto; the opportunity is gone.

The "sure hand" metaphor suggests that not only should we seize opportunities when they arrive but we should do so confidently and decisively. Hesitation or lack of confidence can result in missed chances.

Applying this to today’s world, we live in an era of fast-paced change and innovation. Opportunities can arise suddenly and disappear just as quickly. Whether it’s a job offer, a business venture, a chance to learn something new, or even a fleeting moment to express love or kindness, it’s crucial to act promptly and decisively.

In terms of personal development, this quote encourages us to be proactive and bold. It’s about not waiting for the perfect moment but creating it. It’s about taking risks, stepping out of our comfort zones, and not being afraid of failure. After all, we learn more from our failures than from our successes.

Moreover, the imagery of Fortune being a woman might suggest that opportunities should be treated with respect and not taken for granted. Just as one would treat a woman with respect and not take her for granted, so should one treat opportunities.

In conclusion, Leonardo da Vinci’s quote is a powerful reminder to seize opportunities when they present themselves, to do so with confidence and respect, and to understand that missed opportunities are often irretrievable.