You need time/repetition for new information to sync in. The time needed is inversely proportional to how familiar you are with the subject. For example, I just said what I wanted to say, but now I'll repeat it in another way, because that will make it more accessible: if I already know imperative programming and some logic (?), my absorption of a new related subject - logic programming will be faster; if the most related thing I know is setting the alarm clock on my bedside, the absorption rate will be low and I'll need a lot of learning material for it to sink in.