What does the poet mean when he says that happy man does notserve another's will?

The line you're referring to suggests that a truly happy individual is one who exercises personal autonomy and freedom. Here's a deeper analysis:

1. Autonomy and Independence: The poet implies that happiness is closely tied to self-determination. A happy person does not live their life according to the desires or expectations of others but instead follows their own path and makes choices that resonate with their personal values and desires.

2. Rejection of Subservience: The phrase "does not serve another's will" indicates a refusal to be subservient or to sacrifice one’s own desires for the sake of others. This reinforces the idea that true contentment comes from being true to oneself, rather than conforming to societal pressures or pleasing others.

3. Inner Peace: Serving another's will can often lead to feelings of resentment, frustration, or lack of fulfillment. A happy individual, as per the poet's perspective, has the inner peace that comes from making their own decisions and taking responsibility for their own happiness.

4. Philosophical Implications: This idea is often echoed in philosophical literature, suggesting that happiness is not found in external validation or approval but in an internal sense of alignment with one's true self.

In summary, the poet suggests that genuine happiness is rooted in personal independence and the ability to live according to one’s own will and desires, without being beholden to the expectations of others.