https://rationalwiki.org/wiki/Toupee_fallacy

You only know about the people who let you know. You have no idea how many vegans or airplane pilots you encounter regularly who never tell you. A small sample is driving the reputation of the whole.

For people with whom you talk every day, it’s no surprise that you know. It’s bound to come up but I doubt it happened on your first conversation with everyone. If it did, you were hanging out with a weird group. If they knew each other, it’s normal that they’d talk about a shared interest. Just like people who hang out on HN would be likely to discuss tech when meeting in person.

I have no doubt you found your share of asshole vegans, just like there are assholes who make it a point to make everyone know they eat meat.

Though it is important to distinguish a true asshole from someone simply sharing an experience. Saying “no, thanks, I’m vegan” when offered a bite of a meat sandwich is not bragging, it’s context. Unfortunately, too many people take it to be a judgement when it most often is not.

https://www.youtube.com/watch?v=ExEHuNrC8yU