Well that's the problem - you are basing your belief on anecdote and gut feeling. The actual science behind this is overwhelming - there is nothing wrong with a vegan diet. You won't be able to find much that states otherwise. Beans and whole grains can provide all essential amino acids despite propaganda stating otherwise. Even meat eaters don't get enough B12 and should supplement, because B12 comes from the food animals eat, and their feed is insufficient. If you don't just eat Oreos and white rice, you should be fine as a vegan. The propaganda against veganism will eventually be seen as how the cigarette industry sold cigarettes as healthy.