This quote is a call to action for the young, encouraging them to use their youthful days wisely and productively, as the efforts they put in now will serve as a buffer or compensation for the potential losses or challenges they may face in their old age. The "losses" referred to here could be physical, such as health, strength, or energy, or they could be more abstract, like opportunities, time, or even certain relationships.

Da Vinci is essentially saying that the investments we make in our youth – in terms of our health, our education, our skills, our relationships – will pay dividends in our old age. This is a timeless piece of wisdom that holds as true today as it did during Da Vinci’s time.

In today’s world, this could be applied in various ways. For instance, in terms of personal development, investing time in education and learning new skills can open up opportunities for better jobs or careers in the future. This can lead to financial stability, which can significantly impact the quality of life in old age.

Furthermore, taking care of one’s physical health during youth, through regular exercise and a balanced diet, can help prevent or manage health issues later in life. Similarly, fostering strong, positive relationships can provide a support system that can be leaned on during challenging times.

Lastly, this quote also underscores the importance of saving and investing money from a young age. The earlier one starts, the more time the money has to grow, providing financial security and independence in old age.

In essence, Da Vinci’s quote is a reminder that the actions we take in our youth have long-term consequences, and that it’s crucial to make mindful decisions that will benefit us in the long run. It’s a timeless piece of wisdom that encourages foresight, planning, and mindful living.