Really? I'm not involved in martial arts, but I've never had the impression that someone can become very good very quickly. Maybe in the sense of the one-in-a-million virtuoso in any field, like a child prodigy pianist who is writing a concerto at age 8 or something. For the vast majority of people you're looking at years of training ahead of you to master an artform, and if that seems daunting, the only question is would you rather spend those years making slow and steady progress toward that mastery, or spend those years not making any progress because it's too daunting?