I’m assuming you’re not familar with warrior cats/the cat in question. Ashfur is the cat this person was referring to. Ashfur was the cat who tried to murder Squirrelflight’s father, and throw her kits into a fire to be burned alive, all because she did not return his feelings. He said he wanted to “make you (Squirrelflight) suffer as much as I did!” Saying he was “”“”insane”“”“”  because of his violent and irrational actions is suggesting that all mentally disabled people are violent and irrational.