Frustred, as I just spent a half hour writing out a great post and it completely disappeared. So... the short version: I have a coworker who tells everyone she knows how to do their jobs better than they do (even though she is less experienced, and has different skill sets than others in the office) and recently blew up on me in the most insulting workplace encounter I have ever experienced in my professional life. She insulted me personally, my work ethic, and even alleged that everyone in the office feels the same way she does. In the following days, she has since switched course, being so nice to me, it's making me uncomfortable. In the last two days she has complimented me on everything from my nails, to my hair (three times), my dress, my glasses. It's like she wants be my best friend now and of course, is being a great coworker to boot. This is not the first time she's done this. I thought she just had a problem with me personally, but now I'm starting to wonder if it's not something like bipolar disorder. She is known for crying in the office. She goes through periods where she feeld inadequate and insecure in her job, to thinking she knows better than everyone else. I've tried to communicate better with her, but these blow up/be nice scenarios keep repeating themselves, and seem to get worse. Does she sound bipolar?