In the last 10 years or so, I've tried to go vegetarian several times. The first time was in college, after I learned about the crap that is actually in meat (chickens are fed arsenic!), the cruel treatment of the animals, and the side effects that the meat industry has on the enviroment. It didn't last, because I got too idealistic. It was frustrating to think that my actions weren't visibly changing anything. Worse, I started to feel morally superior about being vegetarian, which made me act like a snob. After a few months I decided it would be better to go back to eating meat just to get over the bad attitude.
Later in college, I tried it a second time. This time, it was for a girl. Everyone in her family was vegetarian. She grew up vegetarian. This really inspired me to go for it. But once again, those feelings of frustration and arrogance became problems, and I stopped.
After college, I tried again. I was making my own meals, so it was more challenging. Grocery stores are chock full of meat products, it's pretty hard to find nutritious and satisfying vegetarian food, and even then a lot of it is bland, a hassle to prepare, or ridiculously overpriced. Several attempts to "go veg" after college failed, each time after a few months, because a ravenous hunger would develop that I couldn't figure out how to satisfy without meat.
With each failure I found some way to justify eating meat again: I decided that I needed more protein, or I heard about some study that said eating meat was really healthy, or I would decide that it was impossible to be vegetarian, or I thought it was good to overcome my idealism. The concerns I had about the animals, the environment, or the health effects of consuming the chemicals in the meat were still there, but I could find an excuse to ignore them.
The problem with those attitudes--both for and against eating meat--was that I was looking for some external reason or authority to tell me what to do. Looking outside my own mind for guidance just led to confusion and hypocrisy. One day, I'd be motivated by my concern for the animals or the environment, but another day I'd be more interested in my own nutrition. One day, I'd hear a compelling reason to eat one way, then later I'd hear a compelling reason to eat another way. In all honesty, there doesn't seem to be any clearly right or wrong way to eat. Diets with and without meat both have benefits and drawbacks, and regardless of which one is healthier, the human body is remarkable resilient and able to survive for decades even on terrible diets. The point is, the issue of diet cannot be resolved through simple analysis of facts.
Clarity came for me when I focused internally and began to think about the emotional and psychological meaning of eating meat. Putting aside the idealism about health, the environment, and even the ideal of having compassion for animals, I investigated my inner motivations for choosing to sustain myself at the expense of living, feeling beings.
The first thing I noticed was the laziness, denial and fear underlying my choice to eat meat: I had frequently chosen to do it because it was the easiest choice, it was a habit, and because everyone else was doing it. I struggled with vegetarianism because I was too lazy to research good nutrition or learn how to make the food enjoyable. That degree of laziness was pathetic, even independent of the fact that it brought excruciating suffering to other beings.
The next thing I noticed was the necessary selfishness inherent in the decision to eat meat. To facilitate the systematic confinement and slaughter of sentient beings just for my personal convenience struck me as extremely selfish. It wouldn't take much sacrifice or effort on my part to spare many animals from a horrible experience. In that sense, vegetarianism could serve as an opportunity to work on my own selfishness.
This became a compelling reason for me to stop eating meat. Selfish actions, I've discovered through careful observation of my personal experience, always come back to bite me in the ass. It's really tempting to deny this fact and lie to myself and say, "I can get away with this one..." but opening my eyes to the big picture of cause and effect in this world eventually brought me face to face with the reality that every action comes to fruition in the future; the seeds you plant turn into the fruit you harvest.
A vegetarian diet is a way for me to plant seeds of care and patience in the action of eating, which is helping me cultivate an attitude of care and patience that seems to be enriching every relationship in my life. It's a way to stop planting the seeds of violence and destruction that must inevitably be planted when eating animals, seeds which come to fruition in subtle and confusing ways in everyday life. Whatever the objective facts may say about meat and nutrition, environment, or cruelty, the unquestionable reality is that it's impossible to eat meat without heightening your sense of self and therefore heightening your sense of alienation from others.
The bottom line is that I'm no longer convinced that eating meat is necessary, and whatever marginal benefits may come from having it in the diet don't outweigh the psychological benefit I've enjoyed from giving it up. At the end of the day, happiness is in the mind, not on a plate.