i don't talk about this with others people unless they ask me or the topic comes out, like last week on my biology class my teacher was commenting about how vegan/vegetarian diet left people without lots of nutrients (wrong btw) with a mocking tone and well i couldn't keep quiet.
If you decide for this diet you'll see the amount of assholes who'll stat/ask lot of bullshit about this. after a while our patience start to wear thin.