Do you make a big thing about not eating meat at every opportunity? I only ask because if so, that may be the reason you're laughed at - if you just reached for the egg sandwich in the canteen, or just quietly ordered the vegetable lasagne, I doubt one person would say anything to you. What get's people's backs up, is when vegetarians start spouting myths like 'the average caarnivore has 7lbs of undigested meat in their bowel' WRONG. If something is in your bowel, it's been digested! Or it takes (I've heard/read anything from 10 - 15 lb) of grain to make 1lb of beef - WRONG again, cows eat mostly grass. I'm sorry if you say none of these things and do go quietly about your business, and if you're laughed at or anybody says something to you again, all you have to say, if anything is, it's your lifestyle choice.