What is the meaning of the swan analogy used in Chapter 17 in the context of human life's purpose?

The analogy of the swan, or Maral, is used in Chapter 17 to illustrate how a wise individual should navigate life. The text explains that just as a swan can miraculously separate and drink only the pure milk when it is mixed with water, a courageous and intelligent person should cling only to Shreya (the Good) and reject Preya (the Pleasant). This act of discrimination is presented as the true purpose of human life (Purushartha), encouraging one to discard worldly attachments and honor the path of wisdom and salvation.