I love black cats, too. I'm told it's because black animals "don't look flash". Grrrrr. Apparently the hardest animal to rehome is an older black dog that's just started to grey a little around the muzzle.
That said, I did have a black cat (Dishrag, my special little guy I had to leave in America when I moved back to this side of the pond) who was... Different
He did have a big white patch on his tummy... But I think he had some superficial brain damage (he was thrown out of a car as a kitten, people really make you wonder don't they? GRRR!)... He was... smart... But he also thought he was a dog
He came if I called him, fetched what I threw and had a magnificent hatred for all things tissue-like.
There again, he did MacGuyver-like stunts to get to catnip or looroll, so I'm going to settle on "different" rather than "stupid"... Here's a picture of him:
I miss him every day.