My first stand-up at the new job and I didn't understand half of what anyone said

Everyone was talking in acronyms and project codenames like it was obvious, and I gave my update in about eight seconds because I genuinely wasn't sure what else to add. Spent the rest of the day convinced they'd made a mistake hiring me.

Mentioned it to my manager in our 1:1 that afternoon, half expecting reassurance I didn't really believe. Instead she just said it takes most new hires three or four weeks before the shorthand makes sense and that's normal, not a signal about competence.

Wrote down every acronym I heard that day and looked half of them up that night. Three weeks in now and I follow maybe 80% of it, which apparently is roughly on schedule.