I've had many slip ups, as well. Not so much as vegetarian, but since I've been vegan for around 2 weeks. Last weekend I was making gardenburgers for myself and bought some vegan cheese, or so I thought. After I was happily eating my delicious meal, I looked at the ingredients...it had casein. :[ The WORST was friday night. My family and I went out to this yummy thai place. I always make sure there is no egg and I got glass noodles as my meal, but stupid me ordered a thai iced tea. I took a big swig and almost puked. I forgot it had cream. :[ I normally get it with soymilk, but just automatically assumed it had it in it. :[ I was so sad.