Sun Wukong has been trapped under Wuzhi Mountain for five hundred years. "He can speak but cannot move his body" (only his head and one hand can move). Moreover, there is a land god under the supervision of the mountain. "He eats iron pills when he is hungry, and drinks copper juice when he is thirsty." The environment is difficult. He could not act as recklessly as before, and could only be forced to "quietly meditate" in restraint.
What have you experienced in five hundred years? Let me tell you slowly...