I adopted (created?) the term "virtual vegan" to describe myself. Do I know with absolute certainty that the popcorn at the movie theater is vegan, or that there isn't a little bit of cheese in the tomato sauce at the restaurant even when they say there isn't? Is there some animal product in the dry wall used to build my house 53 years ago? Do I benevolently imprison my cats in my home against their will? Sort of.
I do the best I can with the information available to me to do what I think is the ethical thing, without driving myself crazy. "If it's stolen from an animal I don't use it" works 99% of the time.