"Travaillez comme si vous deviez vivre cent ans."

Simplified Meaning:

When you take on your tasks, imagine you'll be living for a very long time, say a hundred years. This means putting in effort not just to rush through things, but to do them well because they will matter in the future. Think about a gardener planting trees. They plant small trees, knowing these will take years, maybe even decades, to grow big and provide shade. They don't expect to see the tree fully grown today or tomorrow, but they work carefully and patiently, knowing future generations will benefit from their work. In your life, approach your goals with the same mindset. For example, if you're studying, don't just try to pass the test with quick, last-minute studying. Focus on understanding the subject deeply, so you can use that knowledge later in life. Or if you're building something, like a business or even a relationship, invest time and effort into doing it right. This way, whatever you do will have a strong foundation and be valuable for many years, just as if you were going to be around to see its long-term success.