What challengers did shmuel face in the The Boy in the Striped Pajamas?

In "The Boy in the Striped Pajamas," Shmuel faces numerous challenges, including the harsh realities of life in a concentration camp, where he experiences hunger, fear, and the loss of his family. He also deals with the isolation and dehumanization imposed by the Nazi regime, which strips him of his identity and dignity. Additionally, his friendship with Bruno, a boy from the opposite side of the fence, complicates his situation, highlighting the innocence of childhood against the backdrop of war and prejudice.