The constant cycling. One day I may be the guy with all the answers and the next day (or hour) I may be laying flat on my floor doing breathing exercises).

I'll 2nd the comments about the "I don't give a crap" pill also know as Seroquel. My pdoc just took me completely off it because when I took it I felt like a walker that was mad at everybody for not eating people fast enough (sorry, Walking Dead reference).

I have to say though, my biggest challenge at work is my boss. He's a BP's worst nightmare.