I can’t stress note taking enough. I still have an old notebook filled with HTML notes from back in the day. I don’t know, it’s something about rewriting the topics in your own words that just helps it to sink in better. That and repetition, I know “Practice, practice practice” might sound cliche but there’s truth in it. You might not learn every line of code by heart but you’ll at least do it so many times that the basics will become almost muscle memory. And with the rest, well there’s always your notes and google for that. There’s nothing wrong with looking stuff up, especially if it’s something you haven’t worked with in a while.
My advice is, go back over it and take notes and then do your own mini projects. Get your hands on a text editor (one with syntax highlight is awesome, I personally love Sublime 2). Start with HTML and work your way up.
Like make a menu out of an unordered list, now add some basic styles to it with some simple CSS. Boom you’re done. Next do something with paragraphs and images, play around with floats, text alignment, font sizes, responsiveness.
You can get a stronger grasp on document flow and how block level elements play with each other. How does relative and absolute positioning change the flow? How do floats change it?
How do I center 3 divs horizontally on the page? How do I make them all the same height regardless of the content in them? Stuff like that.
The more you mess around, the more you’ll not only remember it, but understand how to use it.
Another handy thing to is you can take any website and try to remake it. I would say start out with something simple and clean and work your way up, but it’ll give you a good idea what goes into making something like that. And don’t be afraid to look at the source code (or under the hood as I like to call it) and see how a page tics.