Believing something to be true that is clearly not. Someone who is not thinking clearly. Used to describe someone attached to an idea which is obviously false.

A person who gets the vaccine and and flaunts it will high end shopping, trips, and parties

When someone clings to the opinions in their head despite the facts. Often times these people do not want to measure the accuracy of their opinions and believe their situation is overly unique.

So far removed from reality that one fails to think and live in the real world.

Someone who is not thinking clearly, or thinks something will happen that, in all likelyhood, will not.

An individual who is given evidence or proof of an event or some doing. And still refusing to believe.

When someone believes something to be the exact opposite of what it actually is. Such as when someone believes that someone whom they stalk and harass both in person and in cyberspace, thinks only about him/her and misses him/her and loves and longs to be with him/her when in actuality they don't think anything other than you are a pathetic creep/jerk with no life who obviously has a lot to learn in the way of making and maintaining healthy relationships. These are often the same conceited creeps who make futile attempts to make the object of their obsession jealous because they are too ignorant to realize that people are not all like them and that people who are secure with themselves do not get jealous and see their actions as really really lame and pathetic.