Human success and social standing in this world are never permanent, as material reality is constantly shifting and fragile. Because of this unpredictability, a person should avoid resting entirely on their current achievements and instead approach life with modesty, fully aware of how quickly times can change.
True strength, often seen in the form of financial treasure and wealth [אבן עזרא, מצודת ציון], as well as the crown of high status and power [מצודת ציון, ביאור שטיינזלץ], are not guaranteed to last. The primary approach among commentators is that this serves as a practical warning. No matter how vast a person's riches may be, they are not eternal and can easily disappear [רש״י, מצודת דוד]. Furthermore, even if someone manages to hold onto their high rank for their entire life, there is absolutely no promise that this status will remain in the family and pass down to future generations [מלבי״ם].
Since fortunes naturally rise and fall, a person must never look down upon simple, everyday ways of making a living, nor should they neglect the hands-on management of their own property. Someone who stays involved and personally oversees their business affairs while they are wealthy will be much better prepared for hardship. If they ever lose their workers and are forced to labor for their own survival, they will not be broken by the sudden change [עמנואל הרומי, ביאור שטיינזלץ, רש״י].
On the other hand, a more spiritual and philosophical perspective draws a clear line between the physical and the spiritual. While bodily strength and material gains disappear at the end of life, a spiritual crown, such as acquired wisdom, the crown of Torah, or a good name, lasts forever [רלב״ג, אלשיך]. Because of this, a person who loses their money does not lose their inner worth. They should simply continue to work hard and live modestly, keeping their dignity intact rather than lowering themselves to beg for charity [אלשיך].
Ultimately, realizing that earthly possessions fade away like wild grass is meant to wake a person up to look closely at their own character and actions. Understanding that life in this world is temporary should motivate a person to gather spiritual supplies for the journey into the next world, making sure to fulfill all their duties to God and to their fellow human beings [עמנואל הרומי].