One of the articles of faith of autonomous education is that the child wants to learn and will do so happily with minimal coercion, provided there is interest in the subject and appropriate materials and assistance are provided. Even 'downtime' spent playing computer games or watching TV is part of the process, where the brain can organise what it has accumulated. Some computer games and TV programmes are also useful learning in their own right, or can serve as a foundation for a new or renewed interest.
One of the milestones I've looked for in C is a willingness to sit and read non-fiction books for fun, which I remember doing when I was at school, at least in the subjects I enjoyed. It was therefore pleasing to discover that C stayed awake in bed last night until nearly midnight, reading a Horrible Science book from cover to cover. He even remembered it and showed me some of the experiments that he found interesting, so we'll have to do those to reinforce the big step forward. It's also a cue to get some more books at an appropriate level and leave them where he can find them.