Epiphanies start them. The more you fear disbelief, the more you rationalise. They crystallise. Some are dispelled, some can't be.

All have truths stronger, truer, than what is commonly believed. Complete fiction can be truer than (commonly) perceived reality.

It's just rationality, creativity, intuition and belief. The more creative you are, the longer they might last.

Doubting everything helps. Seeing everything as delusional.

Not doubting everything and not being comfortable changing the foundations of your belief system and fear of losing firm ground can lead to more bizarre delusions.

Disorganised schizophrenics or schizomanics are experts at it, I believe. We are willing to, we don't generally fear, changing, "disorganising", very basic assumptions. Much like scientists. Many of us are amateur scientists. It's no coincidence I am.

Mistakes in rationalisations are made. The most common erroneous basic assumption is displacement, sometimes something I call Id-Ego or subconscious-conscious displacement: thinking that some people know what they're doing. They don't. All rationalisations based on those assumptions are of course wrong.

Grandiosity/self-importance is due to people not seeing the truth that you see, I believe, disregarding mistakes in rationality and expression, that leads one to think one is purposely mislead, so it must be important to further expose or use the truth(s).

All of this is delusional: reasoned backwards.

Everyone reasons backwards. Most just aren't enough in touch with their emotions, intuitions, to have many epiphanies.

This is basically how it works. I trust my delusions, strong beliefs.