Peter S. Beagle said this quote
“ I suppose I could understand it if men had simply forgotten unicorns, or if they had changed so that they hated all unicorns now and tried to kill them when they saw them. But not to see them at all, to look at them and see something else-what do they look like to one another, then? What do trees look like to them, or houses, or real horses, or their own children? ”