Milady, we aren't 'ganging up' on you! You are so defensive! We, in the right, are merely pointing out that you are wrong.
The term vegetarian is a not wishy-washy with regards to the consumption of animal flesh: it simply does not include people who even occasionally eat meat. Such people are merely people who don't eat much meat. They aren't vegetarians. Why label yourself at all? There are so many of us countering your arguments because it really is so very very frustrating for the real vegetarians, and you just aren't getting it!
I do actually consider you responsible for perpetuating the ignorance. By even occasionally eating the flesh of an animal, whilst calling yourself a vegetarian, you are telling those around you that vegetarians will occasionally eat meat. Hey, consider this! Perhaps on these rare occasions that you indulge in animal flesh, you refrain instead - maybe your hosts will make better vegetarian options next time, instead of the 'rank' vegetarian options you seem to be offered. And perhaps the next REAL vegetarian your friends encounter won't get lumbered with a fish option because 'well, it was okay for Milady*!
I am firm in my stance, and would rather miss a meal than eat meat (or dairy) - usually ensures I get a decent meal, actually, as people don't think 'oh, AbFab will eat a small bit of chicken/fish, let's not bother making her something decent'!
Potatoes and other vegetables as a lunch offering at school sounds perfectly reasonable. I take it your parents fed you a nutritionally balanced breakfast and dinner, so actually, I think I'd have been fine on a slightly limited seventies school lunch.