[acdha]

It’s not the only one but it’s a very good example of how social dynamics can change with the additional of new knowledge, even if it’s inconsequential for the learner. It’s reportedly better now but my gay friends all have these horrible stories about how people they used to get along with fine cut them off abruptly or even got violent once they came out. Most similar intensity responses are for things like racism where there’s not the surprise whiplash element.

Another one I’d use is leaving an insular religion but the way that works tends to mean fewer people have observed it (e.g. if you don’t hang around with fundamentalists you probably haven’t witnessed it first or second hand).