Exactly! Themes are what I was referring to when I said "grand idea." But it's true that the subtext of a character is intensely important. It's probably the most important thing to figure out before the start of a story, but don't hold the characters back from what they could do. If they're telling you to take the plot somewhere, then go there, I say. The story will unfold into something amazing as long as you keep the themes in mind and stay true to the characters.
The Tumblr Fb app won’t let me post asks without writing a response so I say WELL STATED GOOD (WO)MAN