Conversation

We all have certain opinions that aren't.

That is to say, we hold them, but are unable to defend them from scrutiny, because they aren't opinions, they are feelings.

This is what the word "sentiment" ought to mean, but the dictionary treats it as a synonym for "opinion". We conflate these concepts so frequently that we are unable to keep them separate in our heads.

Humans are extremely skilled rationalisers. Just about any crazy sentiment can be defended through some kind of twisted logic.