> he'd have missed out on his subsequent personal growth

Maybe. Maybe not. People say these kind of things, but it is often a retcon aimed to help them deal with some emotion.

Maybe he would have asked his agent to agree on a deal. The agent would have got him a tiny percentage and he would have spent the money to bring something wonderfull to the world. During which process he would have attained even more personal growth.

Totally made up story, but so is the hint that if he would have had a contract he would have missed out on personal growth.