"I used to be veg*n, but..."

There's a question I've been asking myself lately:

Why do so many people go veg*n but don't stay veg*n?

We're up against powerful forces: generations of tradition, powerful lobbying and a hidden food system. But it's easy to reach out to people -- we have national organizations that give us free literature and videos, there's hours and hours of evidence of cruelty to animals on YouTube, the UN and the World Watch Institute have the most up-to-date research on the environmental aspect, and celebrities like Ellen and Oprah aren't afraid to talk about the issues.

While many people go veg*n as a result of documentaries, leaflets, books and conversations, many do not stick with it. When out tabling or leafleting, or when acquaintances/friends find out I'm vegan, I regularly hear "I used to be veg*n, but..." When I politely inquire about what they had trouble with I hear a range of answers:

"I just felt weak and tired all the time."
"I know it's bad but I just missed meat too much."
"I just don't care anymore."
"I don't know why... I should start doing it again."
"My parents wouldn't cook or buy veg*n food for me." (Haven't heard this much because I'm on a college campus but I know this is a problem for many teens).
"The cafeteria doesn't have enough veg*n options." (While our cafeteria has meager options for veg*ns, I know many veg*ns that have stuck with it despite this. So why does it affect others so much? Next school year this is going to be our top priority).

Some people quit because they say they felt weak and tired all the time, yet I meet some people that are so glad they made the switch because they feel better. If one is trying out veg*nism and they don't feel so healthy, a quick google search returns thousands of results, and I may be wrong, but I'd say most people have a friend/acquaintance that is veg*n to consult if they have questions. Most pro-veg literature has detailed information on eating a balanced veg*n diet or at least links to websites that focus on veg*n health.

Is it a real problem that maybe some people just can't feel healthy without meat? That notion seems so strange to me because I'm very active and rarely sick, but everyone is different and this may be a very real problem for some. I have a friend that used to eat mostly vegan with the occasional animal product. She knows her stuff about nutrition and how to eat a good, balanced vegan diet, but when she started eating more meat/dairy she said she actually started feeling better. It wasn't at the request of a doctor or parent, she just wanted to try it. She still eats lots of vegan food, but more meat/dairy than she used to and says she feels better.

Two years ago I would've said a big problem is that people don't stick with it because they're not involved in a veg*n community or don't have any other veg*n friends, but even though we have a large community at my school, a lot of friends/acquaintances haven't stuck with it or have been on and off despite there being a well-established veg*n community.

When people say they just missed meat too much, I think there's more to it. Every year being veg*n gets easier and more mainstream, so if someone became veg*n several years ago, why is it more difficult for them now?

When it comes to just not caring anymore maybe it's because as people get older they become less idealistic and focus more on their career and starting a family. They may even feel jaded that their idealism in their youth didn't "change the world" like they thought it would. I know this is a blanket statement and obviously there are thousands, if not millions, of exceptions, but I have met many people that say "I was veg*n when I was younger" or used to be involved in a social justice issue during high school or college but have stopped.

What have you found in your experiences and conversations? Has anyone out there reading this fell on and off the wagon in the past? If so, why? And what made you "get back on"? What do you think the problems are? Obviously we know how to expose people to the issues and how to interest them in going veg*n, but why do so many not stick with it?

Are there any articles out there similar to this one that I could read and get ideas from? BeyondVeg.com is a website that addresses these issues but focuses more on raw diets and such (but does talk a great deal of veg*nism).

I'd love to hear what people think and get some discussion and ideas rolling, and figure out the best ways to approach these complex situations.