Hate to break the news to you but most pro boxers have been fighting since they were about 7 or 8 years old. Pro or amateur, still fighting. Alvarez was a youngster fighting in the pro ranks for many years relative to the average other fighter who was wearing headgear fighting that whole time.
Hes beasting right now. Very impressed with how much he has improved over the years. A testament to his determination and ring IQ.