So what makes people dispose of their anti-meat convictions? Many people said that they didn't like how it made them stick out from the crowd, and that they didn't have supportive interactions with fellow vegans or vegetarians. In other words, they didn't feel enough a part of a community. Plus, about two-thirds of the former vegetarians and vegans said they gave up meat or animal products almost immediately after deciding they were going to do so, which means they were capable of quitting their new lifestyle just as abruptly as they started.
Maybe, if you make the important decision to adopt a vegan or vegetarian diet, a better approach would be to introduce it into your life gradually. There's no reason to throw away the entire thing if you feel strongly about it just because you accidentally ate a piece of calamari, confusing it for a french fry. It doesn't have to be so "all or nothing"; instead, eat whatever makes you feel good.
(h/t New York Magazine)