Why did Stanley lie in his letter in holes.?

In "Holes" by Louis Sachar, Stanley Yelnats lies in his letter to his mother to protect his own feelings and maintain a sense of hope. He wants to shield her from the harsh realities of his situation at Camp Green Lake, where he is unjustly sent for a crime he didn't commit. By fabricating a story about enjoying his time at the camp, he aims to reassure her and prevent her from worrying about him. This lie reflects his desire to cope with adversity while still maintaining a connection to his family.