We all slouch on occasion. Personally, my posture is all out of whack due to being one of the taller kids back in school. But, now I'm adult, and realize that my "natural" posture makes me look like I'm not proud of anything I've ever accomplished. It's true that standing up straight can definitely give you a small boost of confidence, and hey — if you start working on your posture now, you'll likely avoid a lot of back issues later. You can't lose.