Writing is Like a Box of Chocolates

I try to have an overall plan. Really I do. But when the characters start talking and acting out, well . . . I never know if I'm going to end up with a chewy caramel nougat or a vanilla creme.

For example. One character is supposed to be scary. Threatening. He's a Teddy Bear! I'm trying to toughen him up so he's more complex and can fulfill his threatening role. It's happening, but slowly.

What's the deal?

Why is it that even when we have defined roles for these characters - who, mind you, we created - they don't conform to our preset definitions for them?

Does it happen because we don't think far enough ahead about how two or more personalities will interact and self-define?

Do they say one tiny little thing in a different tone or perform one act we hadn't counted on that sets them down the road to rebellion before we're even aware?

Do they plot to take us down and write the story themselves?

Or is it our subconscious trying one way after another to make us see something isn't working as it should and this might be one way to fix it?

Or is it trying to show us what we planned isn't working at all and we should chunk it and rethink?

I don't know the answer. I wish I did.

What are your thoughts?