Be extremely careful of «advices» like these, as there's nothing worse than someone bragging about their own ignorance. First, because it appears that despite their many successes commenter still has weak understanding of what theory is and used for. It's not a magical receipe for success, or a subsitute for your creativity. Second, because commenter probably has some special talent that allowed to gain their success. Good for them but you're not them.Third, I'm sure that somewhere along the way they relied on someone else's knowledge of music theory. For example, people like to say Michael Jackson didn't know music theory, but Quincy Jones did, Lukather did, Phillinganes did. Also, Michael knew the «theory» behind vocals and dance moves. Fourth, .knowing what a chord or a scale has never hurt anybody, it can only make you a better musician in the long run