I no longer understand my PhD dissertation
TLDR:  The author independently re-discovered what you may know as Old Code Syndrome.I think that's because mathematical papers place too much value on terseness and abstraction over exposition and intuition.This guy's basically in the position of a fairly new developer who's just been asked to do non-trivial update of his own code for the first time.  All those clever one-liners he put into his code made him feel smart and got the job done at the time.  But he's now beginning to realize that if he keeps doing that, he's going to be cursed by his future self when he pulls up the code a few months later (never mind five years!) and has zero memory of how it actually works.I'm not intending to disparage the author; I've been there, and if you've been a software developer for a while you've likely been there too.Any decent programmer with enough experience will tell you the fix is to add some comments (more expository text than "it is obvious that..." or "the reader will quickly see..."), unit tests (concrete examples of abstract concepts), give variables and procedures descriptive names (The Wave Decomposition Lemma instead of Lemma 4.16), etc.