In She Got Up Off the Couch (and Other Heroic Acts from Mooreland, Indiana), Haven Kimmel writes of her older brother: As a small child, her brother would wheel a tombstone around in a wagon; as a teenager, he decorated his room with wall-to-wall stolen fossils. Ignoring the attention of a succession of popular girls, he ran off, at 18, with a girl who was true but 'other'.
Sounds kind of monotropic to me.
Being monotropic... it's as if you got born with a giant power cord growing out of your back. Plugged into an outlet -- a suitable obsession -- your energy is high and the level of drive and dedication can seem surreal. Unplugged... well, appliances just don't work so well unplugged.
Being monotropic can mean there are times when you're growing up that people see you lying there immobile, and imagine you need a knight-in-shining-armor. But it can be hard to be a knight-in-shining-armor to a person who runs on obsession the way an appliance runs on electricity. (It's a little like hoisting a toaster oven up onto a white horse and expecting it to start doing something.)