I'm annoyed at my girlfriend when we go to the gym
Why do you annoy her at the gym?
She is too picky, always bring things we don't need.
You should be thankful she even cares to try and remember things you might need. You can always go to the gym alone and concentrate yourself.
I don't mind alone. But she probably won't be coming next time so that's good.
That sounds like it's for the best.