A little background:
I have a client, we'll call her Jill. Her and I do not get along. She gets very aggressive with new people. My coworkers told me it takes about 6 months before she trusts people. My arms have been covered with scratches and bruises since I started from her pinching, scratching, and biting me. I went from thinking I could help her, to feeling like I sucked at my job, to just not caring. She's my only client that I dread working with everyday.
My current supervisor is leaving, and the new girl they just hired is getting Jill as her client. I'm pretty relieved that I didn't get that position. I wouldn't want to be responsible for this girl. Its been 3 months and I still have no clue what to do about her. I'm no longer as upset about not getting promoted, because now I know I'm not ready for someone like that.

Re: blessing in disguise
Wow. Blessing in diguise is right. Higher positions come with more responsibility. And in our line of work, the clients get harder and harder.
Happy for you!!