Vegetarianism

Was at Seanna's place last night, and we had a really nice evening with sushi and hot chocolate and a couple of pancakes. Should've used hyla (low-lactose) milk though. I rarely use milk products in the amount that is contained in a cup of hot chocolate, and therefore tend to forget what happens after drinking a cup of a full-lactose milk product.

Among other things we discussed one thing that I've always wondered about in vegetarianism: why is it such a all-or-nothing proposition? Unlike pretty much all other food choices, in our culture "vegetarian" means that you never eat meat or fish, and not, for example, that you normally eat only vegetarian food and only eat meat once in a month or two. Of course there are vegetarians who do in fact eat meat or fish every once in a while, but they are considered to be (temporarily) lapsed vegetarians both by themselves, other vegetarians and even by meat-eaters.

Does not work this way with other food choices. I am, for example, not a coffee drinker. Not that I have a need to define myself as such, but in any situation where the division into coffee-drinkers and non-coffee-drinkers is essential I'd definitely put myself in the latter category. However, I do drink some drink containing coffee maybe several times a year, and neither I nor AFAIK anybody else feel that doing so in any way endangers my status as a non-coffee-drinker. So why does eating meat every once in a while endanger a vegetarian's status as a vegetarian? I can sort of understand it when talking about people who are vegetarian for some ethical reason, but why are people who are vegetarians for a health or taste reason considered to be lapsed vegetarians if they eat meat several times a year?

The only other category where there is some stigma attached to ossacional straying is being a non-drinker, but even in this case I think people can more easily understand a non-drinker who drinks one drink on every big holiday than a vegetarian who eats one steak on every big holiday.