While the books don't explicitly state how he deals with sadness, we can infer based on his character and actions:
* He seeks comfort in nature: As a satyr, Grover is deeply connected to nature. He finds solace in the woods, the sounds of the forest, and the company of other creatures. This allows him to reconnect with his roots and find peace.
* He leans on his friends: Grover's strong bonds with Percy and Annabeth are a source of strength for him. He confides in them, seeks their advice, and finds comfort in their presence.
* He throws himself into his work: Grover is passionate about protecting demigods and finding Pan. He dedicates himself to his duties, using his energy and focus to distract himself from sadness.
* He tries to maintain a positive outlook: Despite his struggles, Grover generally maintains a hopeful and optimistic attitude. He tries to see the good in every situation and find reasons to smile.
It's important to remember that characters like Grover, even those who appear strong and resilient, experience a full range of emotions. Though he may not openly express his sadness, it's a part of who he is and informs his actions and relationships.