I have been reading a lot about vegetarianism. Are you on any special diet. 
I just try to watch what I eat. I have heard vegetarianism has its roots in India and Greece
I am a environmental vegetarian I guess. Industrial animal places are bad for the environment and meat isn't good for humans , or so I've read.
I understand why people practice veganism. Most people do no want to harm animals and prefer a plant based diet.
Supposedly the human digestion system or colon is much longer than an animals because we are supposed to have a plant based diet as opposed to the short colons animals that eat meat have.
I remember reading about some monks who did not eat any meet or use any animals products. But they did choose to eat fish so I guess they were not full vegan.
Yes there seems to be a lot of different varieties of it.  Some don't eat packaged or processed foods that have animal ingredients.
It has changed by now i'm sure but in 2006 the Mintel data showed that the vegan rate in the U.S was between 0.5% and 4%.