Why do you choose to live as a SxE to not smoke, drink, or have one night stands?

I'm just curious what motivates you to not do the following. If you choose not to you are considered Straight Edge. If you do do the following Smoke, drinking, and having one night stands don't respond because you're just proving to me you're illiterate and an idiot. I want to see why some people choose to follow the better lifestyle.