I think some people who are labeled as high-functioning autistic-- including some who are very highly accomplished in their particular field or area of obsession-- share this trait. They almost can't be motivated by their senses. And... they almost can't be motivated by anything but their own particular cause or obsession. I think the difference is taking place at a neurological level.
I think that relates to... Well, I think people mostly just assume that everyone sees it as more pleasurable for a loved one to give them flowers than to run around and squawk like a chicken. I am perfectly capable of understanding that it's supposed to matter to me. The fact remains -- it doesn't. (More about that in a previous post: The Kitty Carryall Metahor).