From the time I found out that meat was animals I felt a little weird about it. When I went away to college I met vegetarians and realized it was a plausible option for me. I later found out about other reasons to be vegetarian, and it was all very interesting. I was vegan for awhile, but after, I don't know, maybe 3 1/2 years, I started craving cheese all the time, and living with my family, it's much easier to eat dairy and eggs. Nowadays, I don't really have a reason for being vegetarian; I just am. After nearly 9 years, I can't imagine not being vegetarian.
A few years ago I came to the decision that I no longer wanted animals to die just so I could eat, clothe myself and groom/clean myself. I'd never consider eating a cat or dog, and cows/pigs/chickens don't suffer any less when they're slaughtered. So I went vegetarian, stopped wearing leather and use cruelty free personal care products.
I originally did it out of purely environmental reasons. I learned about the thermodynamics of food in my highschool bio class, and was astounded by the amount of wasted energy we were pumping into this destructive food system, not to mention after digging deeper into industrial agricultural practices and GMOs... wtf?
After I went vegan, I read more about factory farms (Fast Food Nation), and realized the there is no ethical argument for eating meat. I came to the conclusion that humanity will never have world peace until all life is respected.
Lastly, I practice a lot of martial arts, and saw a boost in my mental and physical health after I stopped living off death. Did some more research about human digestive systems and health.
There is no regret. This is the only way for me.
I'm vegetarian at the moment because I just really love eggs and I'm mad lazy. I plan of getting my own garden and raising my own chickens which I'll treat with love and respect (it's symbiosis, happens in Evolution all the time). 'til then, I'll always eat eggs with a guilty conscience, but I buy free range (whatever that means) in the mean time.