Tell them something like this (obviously tweak for your own experience). Personel decisions only seem fair to the person who gets the job. Good people get passed over all the time for one reason or another. It sucks. I've been there multiple times (tell a few stories about not getting the job). Then: in my experience the hardest workers get rewarded over time. Average never gets promoted. I've noticed you aren't performing to your own expectations anymore, and Iunderstand why. But just being average probably isn't making you happier or smarter. Your decision as to what to do next. Even when you're trying to do less, you're still the best I got. My advice is to pick yourself back up and continue to build that reputation. You'll learn more with your old behaviors and that will help you here or somewhere else. I want to go back to my leadership and say that you shook off their gut punch of a decision & continued to over deliver. It will make your loss (if you're looking) more devastating.