Worry adds to strain. Period. I know I say don't worry a lot but really. If we all sat around worrying that we were going crazy and that you would kill someone you WILL drive yourself mad and poor victim is left bleeding to death wondering what the hell happened. Maybe I'll make you a poster that says in bright cheery florescent colors "Don't worry! Be happy!". Don't jump on the horse expecting to fall because the horse senses that and casually bucks you off. "Ride and never worry 'bout the fall"...