Mariano has scored 14 goals in his first season in France.
He told AS: "I decided to leave Madrid after talking with Zidane and the president. The coach told me that with [Alexandre] Lacazette leaving, it would be a good place for me to show what I can do and score goals.
"We all decided that the best thing for me was to gain minutes and confidence; the chance to show what I can do. I came to Lyon to play and demonstrate to everyone that I could do it, and that's how it's turning out."
He added: "It's all more complicated when you're not playing. But it's also the case that when you're at a club as big as Madrid, you learn from the best every day. I've got that now."