He's a real fruitcake. = He's as nutty as a fruitcake.他真是个怪人。You must have a taste of the fruitcake.你一定得尝尝这水果蛋糕。When he was released, he was as nutty as a fruitcake.他被释放时激动得不能自已。My teacher's a bit of a fruitcake.我的老师有点古怪。He's as nutty as a fruitcake.他疯疯癫癫，行为古怪。