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But relying solely on one's own perception is also not a good idea – it's a very unreliable thing! Let me give you an example.
Personally, this case shocked me. In our neuropsychology, we identify a very interesting syndrome called "Unilateral Right Agnosia" – in this disease (damage to the right hemisphere, impaired visual gnosis – the "intellectual" component of perception, its most important part, without which we would see the world as just blurry color spots), a person stops seeing the left part of their visual field. It's simply fantastic! They really don't see it – they see exactly half. Half of a book, half of a picture (and, by the way, they also draw only half – it turns out to be a kind of even slice of a house), they don't feel (except for extremely strong pain stimuli) the left side of their body – that is, they constantly bump into something with it – and, most importantly, in this disease, they do not realize that they are sick. They think that everything is normal, they complete the missing half of the book... And there was one very sad case – an old man had a severe form of unilateral right agnosia combined with blindness. And he did not realize that he was blind (!). For example, he explained the fact that he was accompanied on the street by saying that he was old and therefore needed help. Once, an experiment was conducted with him – he was given a blank sheet of paper and asked to read what was written on it. It was in Soviet times, the patient was a retired party official, and he took the paper and read it – in his opinion, it was the newspaper "Pravda," and he "read" the title, several headlines, and the usual introductory words...
That's how it is. This is, of course, a pathology, and a very severe one, but it proves that knowledge of what is seen is also a very conditional thing. And that a person, especially one who is eager to see a UFO or has simply read a lot of stories about it, can easily imagine an alien spaceship in an ordinary cloud...
And in general, it's good food for thought :) This is how agnosticism develops :)