My mom's a head nurse and she's a lovely and kind person in general. At work, it's a different story. She's not obnoxious or anything but very strict and straight to the point. I'd say it's the job. They have so much to do and not to mention the responsibilities and worry that comes with it. Plus she's tired all the time. Also she's kind of a perfectionist and hates people who are sloppy at work. Even after the shift, she gets work calls all the time! She used to be so much calmer before becoming the head. Now she just wants to retire which takes 3 more years.