My most consistent pet hate of all: English language 'nazis'. English class for me consisted of (failed) attempts to drag me kicking and screaming into the uncanny valley, interspersed with being immersed in things which made no sense at all. I don't generally go looking for info on the subject, but one time I stumbled across a page detailing how the singular "they" (for when you don't know or don't want to specify gender) has been in use for the entire 700+ year history of Modern English, with even Chaucer writing at the very dawn of the language using something similar. Reading it was something of a vindication.