Your internal dialogue has got to be different from what you say. And, you know, in film, hopefully that registers and speaks volumes. It's always the unspoken word and what's happening behind someone's eyes that makes it so rich. ↗
If you just did a horror tone throughout an entire movie you almost, as an audience, can get a little bit used to it. But if you're laughing one minute and, you know, somebody's doing something quite horrific the next minute, it's a little more shocking. ↗