When we grow up, our idea was changed. When people ask what's becoming a grown up ". After becoming a man selling crepes may also change as the chef. After becoming a coach bag may also change as the accountant.
When we grow up, our thinking has changed. When someone asked why I was growing up. That would be the selling crepes, it may be a chef. It was superseded by the conductor turned Accountants.
When we grow up, our idea is changed. When people asked that want to be when you grow up? From to be selling crepes it could be a chef. From who wants to be a conductor may also change as an accountant.