Currently, it's working with a new co-worker who doesn't respect the people who've been working there longer than her (AKA everyone except her). I work for a company that provides real-time transcription services to deaf and hard of hearing university students and my new co-worker came from a similar, but different company that uses a different system to transcribe.

And even though she went through all of the training to learn our different system (because this is a different job) with rules that everybody abides by, she won't adapt at all. She insists on somehow integrating her old system into this new system and it's making things very very complicated and annoying. If she wanted to keep doing her old job, maybe she shouldn't have gotten fired ;)

It's hard to explain much more of my annoyance because it would require a lot of backstory on what I actually do for my job, but I've never seen somebody so resistant to following a job description... She doesn't realize that her stubbornness is making it so much harder for everyone else. Luckily, I'm not the only one who feels this way.