While its philosophical roots are deep, `四大皆空` is a surprisingly flexible term in modern conversation.
This is its most common dramatic usage. When someone suffers a major setback—losing a business, ending a relationship, failing an important goal—they might use this phrase to express a feeling that their entire world has collapsed and nothing matters anymore.
The term is often used jokingly to describe a state of having “nothing.” The most frequent example is about money.
In more serious or philosophical discussions, it can be used to describe a person who has genuinely let go of worldly desires and lives a simple, unattached life, much like a monk or a sage.