Depends on the paper's content but there's often sections that you don't need to 100% understand to get value. For example, in survey papers, there's typically a section that is basically "what queries we typed in at the library." I skip those and I think you can too =)

For practical papers, sometimes the evaluation can be skimmed. Author's benchmarks are usually designed to be the most favorable to the paper's novel approach, so I don't spend too much time thinking about them.

Similarly, Related Work sections can be skimmed. If you're well read in the field, you probably won't learn anything from it, and if you're entirely unread "its like X but different because Y" isn't helpful as you have no idea what X is, beyond the one dense sentence the paper just gave you.

> And how much of the content would you estimate gets retained and can be recalled when you wish?

If I really want to remember a paper, it goes into Anki flashcards. This is rare, personally. Usually only for tech I support in prod.

I can read and fully understand an ML paper in an hour or so. But 6 months ago it took me a day to get through a couple of ML papers and I did not fully grok the mechanics of things like attention heads.

I'm more read in material science, chemistry, pharmacology, and cognitive science. Computer science (especially quantum computing, networking, and cryptography), photonics, and pure math are also big areas of interest for me.

Anything outside of that wheelhouse will take longer and I'll initially understand less, depending on how distant it is from my stronger subjects.