"I'd gone professional when I was about seventeen"

In this quote, Noel Redding is reviewing his career as a professional artist. He specifies that he had actually made the decision to pursue music as a profession at the young age of seventeen. This suggests that Redding had a strong passion and talent for music at a young age, and was determined to make it his career. It also implies that he had to make a significant dedication and sacrifice at a young age in order to pursue his dream. This quote highlights the devotion and drive that Redding had towards his music profession, and acts as a testimony to his success as a professional artist.