Things I think while re-reading stuff I wrote, a sampler:
There are so many commas in this. WHY are there so many commas in this? Drowning in commas OOH LOOK A SEMICOLON.
This sentence is very convoluted. Where is the end of it? If I turn my head upside down like an owl does it read any better?
Hey, that thing I did there is really rather clever! TOO BAD IT WASN’T ON PURPOSE.
This, all this, is what makes betaing for you the best fun ever!!!! :D
Because sometimes I actually insert notes like this IN THE FIC. Self-snark, it is a way of life, and also conveniently entertainment for beta readers.