Crusoe is lucky because, despite being stranded on a deserted island and facing many challenges and hardships, he is able to survive and even thrive. He is able to find food, shelter, and other resources that enable him to sustain himself, and he is able to use his ingenuity and resourcefulness to overcome many of the obstacles that he encounters. Additionally, he is able to maintain his mental and emotional well-being, which allows him to remain hopeful and optimistic about his situation. Overall, Crusoe's ability to adapt and overcome adversity is what makes him lucky.