Am I the tiger or the tail?
Evolution likely selected for humans adopting the statistically-observed-as-dominant-feelings from their milieu uncritically. It is an optimization: take advantage of others observations and computation, a shortcut that’s fine at small scale in a context where truth is less important than success that may come from group cohesion. See any discussion on the mismatch between the perception of crime, risk, terrorism, etc. drama versus the actual reality for examples of how this goes wrong. The acceptance of mass thinking is the basic reason cults, the folie à deux experience, religions (except yours), mobs, mass hysteria, etc. can exist for ‘rational” beings.
“I just got so swept up in it and it became Really Important at the time…”
The mob is the tiger and goes where it will. The tails follow along, righteously feeling this now, that later, following along as the tiger dashes, turns, and leaps. At any point the tail can tell you a comprehensive theory for why it feels the way it does, just like Alzheimer’s patients construct entirely false explanations for things that never happened. It feels real to them. Being a tail is to have a kind of dementia; when the tail moves on to the next thing, it doesn’t remember the last, it is oblivious now to the Really Important Things from before. Perhaps this is where the story-telling faculty that Alzheimer’s exposes comes from (it’s hardly something added to the brain by the degenerative disease): it’s just the life-of-tail exposed with inadequate, distorted parameters and without hysteresis. Story telling reveals no truths but desire.
This Thing In The Now Is (always) Real.
People get to the other side of these experiences, sometimes, and struggle for the rest of their lives with the idea that they could have believed any of it. They try on different narratives trying to find one that fits but miss the simplest one: all that happened is an idea overwrote their emotion from the outside and they ran with it.
In reality humans oscillate from tail to tiger and back again. Maybe they spend more time as one than the other. The experience is a a sort of iterative prisoners-of-self-dilemma where the prisoner who might betray me is … me.
Imagine a tail wanted to find out whether they were a tail.
One worldview is approximately observed reality, the other is feels-defining-reals. A siamese knight-knave simultaneously is a witness to truth and a teller of lies. What could it ask itself to reveal which half it is? What would a “tail-like” response look like? One dead giveaway, a tail being a tail, would be the urge to choose questions that assume the conclusion one wants, that extend and require the story. In some contexts this approach is called “sanity testing.”
Now imagine a tiger wanted to find out whether there is a ringmaster.
Is this a circus or a savannah? Shade tree .. or cage?
Good luck with that.