What do you want to be when you grow up?

Why do so many people find what they want to do with their lives in mid-life? I know of many middle-aged people who changed careers mid-stream - usually to pursue much more creative pursuits. Having worked in many different fields over the past 30 years I've finally started to listen to that inner voice that has been telling me all my life that I'm a writer and an artist. Even typing those words makes me feel pretentious, however, I'm pushing through that barrier of self-consciousness to explore the creativity inside of me - even if no-one ever reads a word I write, or gazes upon my paintings, because I've realised that it's not about seeking the approval of man, but finding the satisfaction in expression.