I live in the free and morally righteous West and I self censor all the time. Every single day. My beliefs would have me ostracized from communities and fired from my job.
but not landed you in prison or disappeared, I take it?
Not adequately or safely.
https://impactjustice.org/new-report-provides-first-ever-nat...
Was your school worse than that?
It's typical that when someone is arrested for "X action with Y detail" (e.g. buying a knife with intent to kill someone) people who oppose the arrest will only state the X (and for some reason this works). To correct the record when someone says "I don't expect to be arrested for buying a knife", "I do expect to be arrested for planning to a murder" is a correct response.
1. https://en.wikipedia.org/wiki/Political_prisoners_in_the_Uni...
Intelligence and genetics.
Genders and gender specific spaces.
Gender and social/professional roles.
Those are topics which have "sky is blue" level ideological certainty, and not open for debate.