I'm not depressed or have a low self esteem or anything, but I'm one of those geeky-looking guys that slouches his back. I know this is bad, but I revert to that posture when I'm not thinking about it... So I have to remind myself to stand up straight. After a while, my back starts to get strained and it becomes uncomfortable.

Am I doing it wrong? I would think that standing up straight should come naturally... But it feels like I have to force myself to.