I hate to point out the obvious, but it must be done.
People living in civilised societies simply do not understand that there are plenty of uncivilised societies in this world. Those who live in peaceful, advanced societies that have not seen unspeakable violence, destruction, bloodshed, genocide, ethnic cleansing and other heinous crimes against humanity since World War II tend to assume that such things have ceased to exist in the entire world, just because they have not occurred in their part of the world since World War II.
They could not be more wrong! Genocides, ethnic cleansings, pogroms, mass-murders and other such crimes against humanity have been occurring regularly with alarming frequency in Asia and Africa, and to a much lesser extent in Latin America and Eastern Europe, and they still continue to occur to this very day. Even now, the genocide of Ukrainians by barbaric Russkie invaders is not the only genocide that's happening. I can list another half-a-dozen.
I live in a Third World country, in an uncouth, barbaric part of the world. Such things are quite common in this rotten part of the planet.
Another thing people are wrong about is the mindset of the savages who celebrate and cheer on genocide, ethnic cleansing, mass-murders and other crimes against humanity. Civilised people tend to believe everyone else will behave according to their own evolved ethical standards. They are plain wrong.
It is quite silly to assume people who celebrate crimes against humanity behave like sub-human scum because they are dumb, ignorant or lack intelligence. It is not intelligence or knowledge they lack, it is ethical intelligence! They may or may not lack the many other forms of intelligence, but they certainly lack ethical intelligence. Forms of intelligence tend to be independent of each other, and ethical intelligence is the most independent of them all. It is perfectly possible to score very low on an IQ test (that measures only mathematical, logical & analytical intelligence at most) and yet have very high ethical intelligence, and vice versa. Many serial killers are said to have a high IQ (measuring only three forms of intelligence at most), but it should be quite obvious that they have very low ethical intelligence.
To conclude, people in civilised societies need to stop assuming all other societies are civilised, and civilised people need to stop assuming everyone else will have the same ethical standards as them. This would be a good start if one wants to improve the world and make it a better place.