Preferred subjects are not necessarily about refusing to do everything else. Especially in school, we know we need to complete all our subjects to get good grades, but we often put most of our effort, enthusiasm, and energy into the subjects we really enjoy. After that deep focus, we can run out of room in our heads for other things. A computer analogy helps explain it: RAM is like a workbench. It holds what the computer is currently working on. Everybody has a limited amount of mental RAM. Many people can spread it more evenly across different subjects and move between tasks more smoothly. An autistic or ADHD person may have about 90 percent focused on one preferred subject. Background thoughts about that interest can continue using capacity even when we appear not to be doing anything. That can leave only a small part of the workbench for tasks we need to do but are not interested in. It is like having only a two-foot-by-two-foot space left, or only a few megabytes available after a computer is already running demanding tasks in the background. This is why some necessary tasks can take a long time. My mind may still be occupied by a prioritized subject—thinking about the next book, World of Warcraft, or what I want to build in Kerbal Space Program—even when I am supposed to be doing something else. It is not that we are lazy. Most of our brainpower may already be dedicated to a preferred subject, or we may be stuck thinking about what we have to do with the current task.