Moukoko told Danish broadcaster TV2: "I've experienced what it's like to be at the top. I've also experienced what it's like to be at the bottom."
Asked about his time on loan at Nice, he said: "It was really tough. There were nights when I just lay awake thinking about it, I have to be honest. But it taught me to be humble, to keep my feet on the ground and not to be arrogant.
"I think it made sense for me to go through that. There were a lot of critical stories about me. In Nice, they wrote that I was out of shape. But I trained harder than ever before. I trained three times a day on my own and discovered a new motivation within myself.
"I don't care what people say or write about me. Whatever it is, I just laugh about it. I trust myself and my body. I feel that I really want to play again."