Well, the day arrived.
I finally looked a little too off, was a little too slow to smile, and my niece asked me the question I've dreaded answering "Why are you sad?"
In this case, I was able to deflect. "I'm just very tired," I told her. It wasn't a lie; I was exhausted. But it wasn't the truth, either. At least, it wasn't the entire truth.
I've always thought that, when the time is right, I'll be open with Niece and Nephew about my mental health struggles, because I'm terrified that either or both of them will turn out to have the same problems I've faced and don't want them to suffer alone. Neither of them, however, is at an age where they can adequately grasp the depth of anxiety and depression. Possibly they won't even understand the concept; for their sake, I hope they don't, because that would be a horrible thing to know when you're so young.
The thing is, they're inquisitive, and Niece has already been labeled gifted, so I expect more moments like these will arise whether I want them to or not. And to date, this is the worst part of depression I've had to face. Everything else seems easy compared to the anguish of knowing I've let the kids see me this way.
I hope it will all make sense to them in the future. I just don't want it to have to make sense right now.