Our DD is similar in that she doesn't want to share. She can go a few days, a few weeks and even a few months before revealing that she understands it. I link it to her perfectionism. She is not comfortable sharing until she is sure she gets it. If we ask her about it we get the famous "I don't know". I have learned a while back to leave her alone and she finally comes around.
As for the computer part ... I see her vocabulary as an example. During conversation or watching TV, etc she picks up a large word and asks us what it means. (Sometimes she just gets the meaning with how it is used.) Days and weeks go by and she never brings it up but when a situation is just right and the word can be pulled out she always does. It is as if she stored it away in a folder and yes that is schema but it is normal for a child to need repetition on the subject yet this kid doesn't seem to need it. If it peaked her interest it is almost guaranteed she has it stored.
