I'd like to think I was an introspective child. I certainly tend to be introspective now, so that hasn't changed too much. What has changed is the subject of the introspection and the potential role.
As a child, I didn't have to concern myself with why I was concerned about the future. It's just a natural element of being young. Kids don't have the background knowledge necessary to make rational predictions about the directions they're heading, so they're left with nothing but imagination. A bit of creative thought tends to push introspection toward the fantastical, of course, so it's difficult to even begin to consider such mundane concepts as "where will I be living a decade from now". None of those thought processes really mattered, though! They didn't need to resolve any issues and were really just fun.
That's potentially the greatest loss inflicted by adulthood: the inability to think without purpose or intent. Maturity brings so many issues to face each day that any choice which doesn't work to solve such issues resembles avoidance. I genuinely miss the opportunities to be purely creative. Sure, it's easier to realize your influences as youthful naïveté erodes, but at least a portion of that childish imagination is the sincere willingness to disregard intent, at least briefly. I can never get that back.