How do you remember new things in your brain? Do you try to remember it as an index? or will you try to save entire information?

As an example- When reading HN, if I find something intresting I try to read the entire post so I can use new learnings in the future.

Sadly, I tend to forget about it in a week or two. To overcome this probem I started creating a file which has keywords and links to articles (like an index page on the book) and it started helping me.