someone just told me I was willing to die on a hill for my opinion

Yeah I saw that one, that was... Weird as hell.

This may not be the case here, but idioms like this can sound particularly weird when they're in a language that isn't your first language

Or when you're autistic, which is the case here, I'm a native English speaker xD

It is about steadfastly holding to an unpopular (...) opinion in the face of adversity.

Yeah, I frequently don't share those opinions to avoid the adversity. Not all of them, hell if you sort by "Most controversial" on my profile there's some good examples of me dying on a hill. More just the quiet beliefs that shape massive swathes of my worldview that I don't talk about frequently for one of a number of reasons.

Think that one might be the root of why this thought occurred to me, tbh; the difference between the opinions I hold that I will actively argue in favor of, vs the ones I hold that I don't really talk about in any context because, while they're important to me, they're not worth arguing over.

You said you have a few opinions you would be willing to die for. That's probably a bit more extreme than this phrase is intended for.

Fair, yeah. I tend to overanalyze these things, it's fun for me xD