I think that specific reasons for being edge will always be different for every person you ask, but the basic idea is to live by a code of integrity that keeps you healthy and in control of every aspect of your life, above the influences of drugs, alcohol and irresponsible behaviors like promiscuous sex. Being vegan is separate from being edge, but many people are both and consider them to go hand in hand. I could go on and on about why I'm edge, but it usually gets pretty preachy sounding and pisses people off. While this usually entertains me quite a bit, I've had a long day so I'll skip it this time.