Types of learning

I'm expecting to encounter 3 different types of learning as I get to each topic needed to make this site:

1. I used to know about this, but it's been a long time and I've forgotten
2. I never knew too much about this to begin with
3. Lots of what I did know is out of date, things have changed

As an example: last year I started learning JavaScript, and found all 3 of these reasons applied. Type 1 because it's been years since I used it, and lots of things are different from languages I'm more used to. Type 2 because I never used it all that much, or for anything very complicated - so I wasn't very expert even before forgetting things. And type 3 because JavaScript has come a long way in the meantime (there's so many improvements!). Surprisingly, it still didn't feel like I was starting completely from scratch, enough of what I remembered still applied to feel like a useful head start.

I might adjust this list of learning reasons if I realise something else fits better. Maybe there's some kind of standard list that applies?