this is ironic but, constant complaining. I mean, it's fine to mention it once or twice to different people but when someone just keeps saying it and saying it... it gets old in around 4 seconds.
also, when people cannot find it in them to be even remotely professional when needed, i.e. in school during a lesson, on a job, volunteering etc. people have control of their actions, and they need to learn to keep them in check.
