How does the theme of perseverance apply to Salva?

The obstacles Salva faces are formidable, to say the least. He is forced away from home, endures starvation and dehydration, almost has to fight in the war, almost drowns, and almost gets eaten by crocodiles. He loses not just family but also friends in his journey, and he wishes he could give up numerous times. Nevertheless, Salva perseveres. He isn't perfect, but he demonstrates a willingness to just keep going even though the situation is difficult and seemingly hopeless. He is an inspiring figure and one worthy of emulation.