Exactly! Scientific papers are not meant to stand on their own -- they are pieces of a much larger jigsaw puzzle. In order to make heads or tails out of a paper

Exactly! Scientific papers are not meant to stand on their own -- they are pieces of a much larger jigsaw puzzle. In order to make heads or tails out of a paper, one really needs to have a sense of where the paper fits into its larger picture. Building up necessary base of knowledge to develop that sense, both in terms of explicit knowledge and tacit knowledge, is part of what a PhD student is actually doing while they are working on their PhD, and is part of why the process takes as long as it does. Also, the mechanical process of effectively reading a paper is highly non-linear, and is a skill in and of itself. In a lot of ways, it is more akin to high-level pattern matching than it is to more "normal" reading. At least at my institution, it is something that we actually teach our students to do in formal ways (the obligatory "How to read a scientific paper" lecture during the first term or two) and then make them practice over and over again for years (journal clubs, etc.). The original author eventually figured this out, which is to their credit.