There is a more or less gregarious social drive in every individual, and most people are terribly uncomfortable unless they follow the same line as their fellow men (or cows, in this case).
Erich Fromm said "An illusion shared by all becomes reality".
In fact, as Mark Twain wrote, "It is much easier to deceive people than to convince them that they have been deceived".
But Abraham Lincoln, who was no ordinary fool like me, said one day, "You can deceive everyone for some time and someone forever, but you can't deceive everyone forever."