I am extremely dissatisfied with the phrase “he lives in another world” to understand him that he does not agree with you, because we all live in the same world. But a good option is “he sees that the world is different (perhaps falsely)”, exactly so, because “he sees the world differently / in a different way” has connotations of just an opinion to which everyone is entitled, and “he sees a different world” again creates the feeling that there are other worlds in which some people may not live, but look exclusively at them. The same glasses of perception. Trying to tell people to “take off your wrong glasses” is useless because first, if they just take off their glasses, they won’t see anything, people are born completely nearsighted, which can be seen from babies, besides, human eyes have a blind spot and other defects, which need to be corrected with glasses, secondly, they see that their glasses do not create any distortions of the normal / ordinary picture of the world, but they see that our glasses distort reality. The glasses metaphor is already known here and there, has no wrong connotations and is quite intuitive. In addition, now all people know about visual illusions, so it will be clear to everyone that we can literally SEE the world in different ways, see things differently than they really are. This metaphor may look obvious, but for a long time it did not occur to me in the correct formulation, it is desirable to develop it and make it commonly used. “Point of view” is a fixed expression, but it does not imply that the point of view can be wrong, either literally or figuratively.
However, the reception with the worlds will also be effective: “they believe that they live in another world.”
I am extremely dissatisfied with the phrase “he lives in another world” to understand him that he does not agree with you, because we all live in the same world. But a good option is “he sees that the world is different (perhaps falsely)”, exactly so, because “he sees the world differently / in a different way” has connotations of just an opinion to which everyone is entitled, and “he sees a different world” again creates the feeling that there are other worlds in which some people may not live, but look exclusively at them. The same glasses of perception. Trying to tell people to “take off your wrong glasses” is useless because first, if they just take off their glasses, they won’t see anything, people are born completely nearsighted, which can be seen from babies, besides, human eyes have a blind spot and other defects, which need to be corrected with glasses, secondly, they see that their glasses do not create any distortions of the normal / ordinary picture of the world, but they see that our glasses distort reality. The glasses metaphor is already known here and there, has no wrong connotations and is quite intuitive. In addition, now all people know about visual illusions, so it will be clear to everyone that we can literally SEE the world in different ways, see things differently than they really are. This metaphor may look obvious, but for a long time it did not occur to me in the correct formulation, it is desirable to develop it and make it commonly used. “Point of view” is a fixed expression, but it does not imply that the point of view can be wrong, either literally or figuratively. However, the reception with the worlds will also be effective: “they believe that they live in another world.”