John - this is a "truism" that has been said (maybe in slightly differing words) by so many - and as such I doubt if it can be attributed to one individual. Without knowing the context it's difficult to advise further. However, you might like another quote that can be attributed - "I never met a guitarist I couldn't learn something from" - Chet Atkins.
Both underline a similar theme of individuality being the paramount ideal in a self-expressional art form (that one was me

). Best wishes with the project.